function check()
{
if(document.form.email.value =="")
	{	
		alert(" Please fill in Email");
		document.form.email.focus();
		return false;
	}
	if (document.form.email.value != "") 
	{ 
	C=document.form.email.value.indexOf("@"); 
	B1=document.form.email.value.lastIndexOf("@");
	B=document.form.email.value.lastIndexOf(".");
	A=document.form.email.value.length-1;
	if ((C!=B1 || C<1 || B-C<2 || A-B>3) || (C!=B1 || C<1 || B-C<2 || A-B <= 1))
		{
		alert("Please fill in a valid E-Mail Address!!");
		document.form.email.focus();					
		document.form.email.select();
		return false;
		}				
	else
		{
		enter = document.form.email.value; 
		var stringidx = enter.search("@");
		var string1 = enter.substring(0,stringidx);
		}
if ( !isChars( (string1), "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890._" ))
		{
		     	alert( " Invalid emailid" );
			document.form.email.focus();
			document.form.email.select();
		    	return false;	 
			}
		}
return true;
}
function isChars(s, s1){  
    	var i;
     	for (i = 0; i < s.length; i++){   
         	var c = s.charAt(i);
        	if (s1.indexOf(c) == -1) return ;
    		}

return true;
}