// JavaScript Document
function checkFeedback()
{
	var name = document.form_feedback.name.value;
	var email = document.form_feedback.email.value;
	var altemail = document.form_feedback.altemail.value;
	if(name.length==0)
	{
	  alert("Please enter Your Name.");
	  document.form_feedback.name.focus();
	  return false;
	}
	if(email.length==0)
	{
	  alert("Please enter Your Email ID.");
	  document.form_feedback.email.focus();
	  return false;
	}
	if(isValidEmail(email) == 0)
	{
		document.form_feedback.email.focus();
		return false;		  
	}	  
	if(altemail.length>0 && isValidEmail(altemail) == 0)
	{
		document.form_feedback.altemail.focus();
		return false;		  
	}	  
	return true;
}

function isValidEmail(emailid){		
	var l = emailid.length;
	if(l==0)
		return false;	
	if(l!=0)
	{
		var a = emailid.indexOf('@');
		var d = emailid.lastIndexOf('.');
		var str1 = emailid.substr(0, a);
		var str2 = emailid.substr(a+1, d-a-1);
		var str3 = emailid.substr(d+1, l);
		var len1 = str1.length;
		var len2 = str2.length;
		var len3 = str3.length;
		if(a<0 || d<2)
		{
			alert ("Check for missing '@' or '.' ");
			return false;
		}
		else if (a>d)
		{
			alert ("Invalid email. Please enter correct email address");
			return false;
		}				
		if (len1<=1 || len2<=1 || len3 <=1)
		{
			alert ("Invalid email. Please enter correct email address");
			return false;
		}				
	}
	return true;
}