function echeck(str)
{
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	if (str.indexOf(at)==-1)
	{
		alert("Invalid E-mail ID");
		document.getElementById("email_add_sub").value = "";
		document.getElementById("email_add_sub").focus();
		return false;
	}
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
	{
		alert("Invalid E-mail ID");
		document.getElementById("email_add_sub").value = "";
		document.getElementById("email_add_sub").focus();
		return false;
	}
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr)
	{
		alert("Invalid E-mail ID");
		document.getElementById("email_add_sub").value = "";
		document.getElementById("email_add_sub").focus();
		return false;
	}
	if (str.indexOf(at,(lat+1))!=-1)
	{
		alert("Invalid E-mail ID");
		document.getElementById("email_add_sub").value = "";
		document.getElementById("email_add_sub").focus();
		return false;
    }
	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
	{
		alert("Invalid E-mail ID");
		document.getElementById("email_add_sub").value = "";
		document.getElementById("email_add_sub").focus();
		return false;
	}
	if (str.indexOf(dot,(lat+2))==-1)
	{
		alert("Invalid E-mail ID");
		document.getElementById("email_add_sub").value = "";
		document.getElementById("email_add_sub").focus();
		return false;
	}
	if (str.indexOf(" ")!=-1)
	{
		alert("Invalid E-mail ID");
		document.getElementById("email_add_sub").value = "";
		document.getElementById("email_add_sub").focus();
		return false;
	}
	return true					
}

function chkform()
{
	if(!echeck(document.getElementById("email_add_sub").value))
	{
		return false;
	}
}