//this script holds email checking functions

function isEmail (str) 
{
	var supported = false;

	// check if regular expressions are supported (v4 browsers)

	if (window.RegExp) 
	{
		var tempStr = "a";
		var tempReg = new RegExp(tempStr);
		if (tempReg.test(tempStr)) 		
			supported = true;		
	}
    
	var ok = "1234567890qwertyuiop[]asdfghjklzxcvbnm.@-_QWERTYUIOPASDFGHJKLZXCVBNM";

	for (var i = 0; i < str.length ;i++)
	{
		if(ok.indexOf(str.charAt (i)) < 0)
		{ 
			return (false);
		}
	}    
    
	// if we're running an old browser, do a simple check

	if (!supported)
		return (str.indexOf(".") > 2) && (str.indexOf("@") > 0 && str.indexOf("'") == -1);
	else
	{
		// we're running a v4+ browser so do a more sophisticated check
	
		var r1 = new RegExp ("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
		var r2 = new RegExp ("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$"); 

		return (!r1.test(str) && r2.test(str) && str.indexOf("'") == -1); 
	}
}