// JavaScript Document
function validateUserName()
{
var regex = /^([a-zA-Z0-9_\.])+$/;
if(!regex.test(document.form1.username.value))
{
alert("Invalid username format");
return false;
}
return true;
}


function isBlank(str)
{
	if(str.length==0)
		return true;
	else
	   	return false;
}

function checkname()
{
	if(isBlank(document.form1.name.value))
	{
		alert("Name field can't be empty");
		return false;
	}
	else
		return true;
}

function checkcomments()
{
	if(isBlank(document.form1.comments.value))
	{
		alert("Comments field can't be empty");
		return false;
	}
	else
		return true;
}

function checkemail()
{
	if(isBlank(document.form1.email.value))
	{
		alert("Email ID field can't be empty");
		return false;
	}
	else
		return true;
}

function emailvalidation(str)
{
        value = str;
        apos=value.indexOf("@");
        dotpos=value.lastIndexOf(".");
        lastpos=value.length-1;
        if (apos<1 || dotpos-apos<2 || lastpos-dotpos>3 || lastpos-dotpos<2)
        {
                alert("Email entered is in wrong format");
                return false;
        }
        else
        {
                if(/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i.test(value))
                {
                        return (true)
                }
                else
                {
                        alert("Email entered is in wrong format");
                        return (false)
                }
        }
}

function checkform()
{
	if (checkname()==false)
	{
		document.form1.name.focus();
		return false;
	}
	if (checkemail()==false)
	{
		document.form1.email.focus();
		return false;
	}
	if (emailvalidation(document.form1.email.value)==false)
	{
		document.form1.email.focus();
		return false;
	}
	if (checkcomments()==false)
	{
		document.form1.comments.focus();
		return false;
	}
}