function isBlank(s)
{	
//alert("isblank")	
	for(var i=0; i<s.length; i++)
	{		var c=s.charAt(i);	
			if ((c !=' ') && (c != '\n') && (c !='\t') && (c != '')) 
			return false; 
	}	
return true;
}
function isNumeric(s)
{	
	for( var i = 0; i < s.length; i++ )	
	{		
		var c = s.charAt(i);		
		if( c < '0' || c > '9' ) 
		return false;		
	}	return true;}
	
// isEmail v1.0 // to check the user's email address...
function isEmail(s){		// declare the working variables
var emailLength, notFound, atSign, firstPeriod, lastPeriod, whereAtSign, space;	
// pull in the values for the variables	
notFound 	= -1;								
// set notFound to -1, equals the result of indexOf if the character is not found	
atSign		= s.indexOf("@"); 					// Get where the @ sign is	
emailLength = s.length; 						// what is the length	
firstPeriod = s.indexOf("."); 					// get where the '.' is	
lastPeriod 	= s.lastIndexOf(".", emailLength-1) // get where the end '.' is.  If there is one at the end.	
space 		= s.indexOf(" "); 					// are there any spaces (should return -1 for none)	
whereAtSign = (emailLength-1) - atSign; 		// figure out where in the address the @ sign is.		
												// use the next line for debugging.	
												//alert(firstPeriod +" - "+lastPeriod +" - "+whereAtSign);		
												// If any of the following are true, this will return false, otherwise, it is a 
												//well formed email address.						
												// @ and '.' are not found	
												// the last '.' in the address is before the '@'	
												// the @ sign is too close to the end of the string	
												// there are any spaces in the address.	
if(atSign == notFound || firstPeriod == notFound || lastPeriod < atSign || whereAtSign < 2 || space != notFound)		
	return false;	
else		
	return true;
}