/*-------------------------- Some JavaScript utilities --------------------------------

This file contains source code of some utilities that are used usually  in JavaScript 
programming:
- isDigit : test it a character is a digit or not.
- trimLeft : cut leading blank spaces of a string.
- trimRight: cut trailing blank spaces of a string.
- trim: cut all leading and trailing blank spaces of a string
- isPosInt: test if a string has the format of a positive integer number or not.
- isPosReal: test if a string has the format of a positive real number or not. The decimal 
			 separator must be ".".
- isValidDate: test if a string has the format of a valid date or not. Format :mm/dd/yyyy
- isEmail: test if a string is a valid e-mail address or not
- isZip: test if a string has the format of a US zip code or not.
- getFileName: return the file name form the full file name.
- getFileExt: return the file extenstion from the full file name.

History:
- Jan 2 2001 : 
	Update the isValidDate to allow the user to specify the format of date.
	Support 2 kinds of date : mm/dd/yyyy and dd/mm/yyyy 
- Jan 13 2001
	Update the isValidDate to allow the user to specify the format of date.
	Support 4 kinds of date : mm/dd/yyyy,dd/mm/yyyy,mm/dd/yy,dd/mm/yy. 
*/

/*--------------------------------Implementation ---------------------------------------*/

/*
isDigit
Check if a character is a digit or not
*/
function isDigit(c)
{
if((c=='0')||(c=='1')||(c=='2')||(c=='3')||(c=='4')||(c=='5')||(c=='6')||(c=='7')||(c=='8')||(c=='9'))
	return true;
else
	return false;
}

/*
 trimLeft
 Remove all spaces at the beginning of a string
*/
function trimLeft(s)
{
 var i;
 i=0;
 var n;
 n = s.length;
 while((i<n)&&(s.charAt(i)==' ')) i++;
	s = s.substring(i);
 return(s);
} 

/*
 trimRight
 Remove all spaces at the end of a string
*/
function trimRight(s)
{
 var n;
 n = s.length;
 var i;
 i = s.length-1;
 while((i>=0)&&(s.charAt(i)==' ')) i--;
	s = s.substring(0,i+1);
 return(s);
}

/* 
 trim
 Remove all leading and trailing spaces in a string
*/
function trim(s)
{
 s = trimLeft(s);
 s = trimRight(s);
 return(s);
}  

/*
 isPosInt
 check if a string is a valid positive integer
*/
function isPosInt(s)
{
 var n;
 n = s.length
 if(n==0) return false;
 for(i=0;i<n;i++)
	if(!isDigit(s.charAt(i))) return false;
 return true;
}

/*
 isPosReal
 check if  a string is a valid positive real number or not (. as decimal number)
*/
function isPosReal(s)
{
 var dot;
 s = trim(s);
 dot =0;
 for(i=0;i<s.length;i++)
	if(!isDigit(s.charAt(i))) 
		{
			if(s.charAt(i)=='.') 
				{
					dot++;
					if(i==s.length-1) return false;
					if(dot>1) return false;
				}
			else return false;	
		}
 return true;
}

/*
 isValidDate
 check if a string is a valid date. The format of date can be specified 
 1- is mm/dd/yyyy
 2- is dd/mm/yyyy
 3 -is mm/dd/yy
 4 -is dd/mm/yy 	
*/
function isValidDate(strDate,intFormatDate)
{
 var m;
 var d;
 var y;
 var i1;
 var i2;
 
 if((intFormatDate!=1)&&(intFormatDate!=2)&&(intFormatDate!=3)&&(intFormatDate!=4)) return false;

 strDate=trim(strDate);
 if(strDate=="") return false;
 i1 = strDate.indexOf("/")
 if(i1<0) return false;
 
 if((intFormatDate==1)||(intFormatDate==3))
 	m = strDate.substring(0,i1);
 else
	d = strDate.substring(0,i1);

  
 i2= strDate.indexOf("/",i1+1)
 if(i2<0) return false;

 if((intFormatDate==1) || (intFormatDate==3))
	d = strDate.substring(i1+1,i2);
 else
	m = strDate.substring(i1+1,i2);
 
 y = strDate.substring(i2+1)

 if((m=="")||(d=="")||(y=="")) return false;
 if((m==0)||(d==0)) return false;
 if(!isPosInt(m))
 	 return false;
 else
 	{	
	 m = parseInt(m);
	 if(m>12) return false;
 	}

 if(!isPosInt(y))
 	 return false;
 else
	{
	 y = parseInt(y)
	 if(y>9999) return false;
	 if((y>=100)&&(y<1900)) return false;
	}

 if(!isPosInt(d))
 	 return false;
 else
	{
	 d = parseInt(d)
	 if((m==1)||(m==3)||(m==5)||(m==7)||(m==8)||(m==10)||(m==12))
		 if(d>31) return false;
 	 if((m==4)||(m==6)||(m==9)||(m==11))
		if(d>30) return false;

	 if(m==2)
		{
		 if(d>29) return false;
		 if((y%4)!=0) // not a leap year
		 	if(d>28) return false;
		}
	}

return true
}

/*
 isEmail
 check if an email address is valid (format only) 
*/
function isEmail(strEmail)
{
 var intlen;
 var ctmp;
 strEmail = trim(strEmail);
 if(strEmail=='') return false;
 intlen=strEmail.length;
 if(intlen<5) return false;
 if(strEmail.indexOf('@')==-1) return false;
 if(strEmail.indexOf('.')==-1) return false;
 if(intlen - strEmail.lastIndexOf('.') -1 > 3) return false; 
 if((strEmail.indexOf("_")!=-1) && (strEmail.lastIndexOf("_") > strEmail.lastIndexOf("@"))) return false;
 if(strEmail.lastIndexOf(".") <= strEmail.lastIndexOf("@")+1)  return false;
 if(strEmail.indexOf("@")!=strEmail.lastIndexOf("@")) return false;
 if(intlen -1 == strEmail.lastIndexOf('.')) return false;
 if(strEmail.charAt(strEmail.indexOf('@')+1)=='.') return false;
 if(strEmail.indexOf(" ")!=-1) return false;
 if(strEmail.indexOf("..")!=-1) return false;
 
 strEmail=strEmail.toLowerCase();
 for(intcnt=0;intcnt<intlen;intcnt++)
	{
	 ctmp = strEmail.charAt(intcnt)
	 if((!isDigit(ctmp))&& ((ctmp>'z')||(ctmp<'a')) && (ctmp!='-') && (ctmp!='.') && (ctmp!='@') && (ctmp!='_')) return false;
	}

return true	;
}

/*
 isZip
 receive  a string, return true if it has a valid format of US 5 digits zip code.
*/
function isZip(str)
{
 str=trim(str);
 if(str=='') return false;
 if(str.length!=5) return false;
 if(!isPosInt(str)) return false;
 return true;
}

/*
getFileName
receive a full path file name, return only the file name
	ex: input = C:\Windows\myfile.txt
	output = myfile.txt
*/
function getFileName(str)
{
 var bpos
 var filename
 if((str=='')||(str.indexOf("\\")==-1)) return(str);
 bpos = str.lastIndexOf("\\");
 filename = str.substring(bpos+1,str.length)
 return(filename);
}

/* 
 getFileType
 receive a full path file name, return only the file extension
 ex: input = C:\Windows\myfile.txt
  	 output = txt
*/
function getFileType(str)
{
 var filename;
 var fileext;
 var dotpos;
 fileext ='';
 filename = getFileName(str);
 dotpos = filename.lastIndexOf(".");
 
 if(dotpos!=-1)
	{
		fileext = filename.substring(dotpos+1,filename.length);
		fileext = fileext.toLowerCase();
	}
 else
	{
		fileext = '';
	}
 return(fileext);
}


//These functions for validate program display

function IsValidTime(timeStr) 
{
	var hour, minute, ampm;
	var timeStrValue = timeStr.value;
	var timePat = /^(\d{1,2}):(\d{2})(:(\d{2}))?(\s?(AM|am|PM|pm))?$/;

	var matchArray = timeStrValue.match(timePat);
	if (matchArray == null)
	{
		alert("Invalid Time format. Time format is hh:mm(am|pm)");
		timeStr.focus();
		return false;
	}
	hour = matchArray[1];
	minute = matchArray[2];	
	ampm = matchArray[6];
		
	if (ampm=="")
	{ 
		alert("Invalid Time format. Time format is hh:mm(am|pm)");
		timeStr.focus();
		return false;		
	}

	if (hour < 0  || hour > 12) {
		alert("Hour must be between 1 and 12.");
		timeStr.focus();
		return false;
	}
	if (minute!=0 && minute!=15 && minute!=30 && minute!=45)
	{
		alert("Minute must be 0 or 15 or 30 or 45 number.");
		timeStr.focus();
		return false;
	}	
	return true;
}


//check numeric string
//receive the string => return true or false
function CheckDecimalNumeric(szcheckStr)
{
	var pos
	var AcceptedChars = "0123456789.";
	var allValid = true;

	for (i = 0;  i < szcheckStr.length;  i++)
	{
	  ch = szcheckStr.charAt(i);
	  for (j = 0;  j < AcceptedChars.length;  j++)
	    if (ch == AcceptedChars.charAt(j))
	      break;
	    if (j == AcceptedChars.length)
		{
		  allValid = false;
		  break;
		}
	}
	if (!allValid)
		return false;
	else
	{
		pos=szcheckStr.indexOf(".");
		if (pos>0)
		{
			if (pos==szcheckStr.lastIndexOf("."))			
			{
				return true;
			}
			else
			{
				return false;
			}
		}
		else
		{
			return true;
		}
	}
}