function checkvalid()
{
var ename=false;
var email=false;
var sub=false;
if(document.myform.name.value!='')
ename=true;
if(document.myform.mail.value!='')
email=true;
if(document.myform.txtarea.value!='')
sub=true;
if(!ename)
{
window.alert('Name is mandatory');
document.myform.name.focus();
return false;
}

if(!email)
{
window.alert('Mail is mandatory');
document.myform.mail.focus();
return false;
}
if(!sub)
{
window.alert('Comments should not be empty');
document.myform.txtarea.focus();
return false;
}
return true;
}



function chkmail()
{

x=document.myform
email=x.mail.value.indexOf("@")
dot=x.mail.value.indexOf(".")
if (email == -1)
	{
	alert('Not a valid e-mail');
	document.myform.mail.focus();
	return false;
	}
if(dot==-1)
{
	alert('Not a valid e-mail');
	document.myform.mail.focus();
	return false;
}
}