function is_email(e) {
var ereg = /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z09]+$/;
return ereg.test(e); 
}

function validateform()
{
if(document.getElementById("fname").value.length==0)
{ alert("Please enter your name"); return false; }

else if(document.getElementById("emailid").value.length==0)
{ alert("Please enter your email address"); return false; }

else if(!is_email(document.getElementById("emailid").value))
{ alert("Please supply a valid email address"); return false; }

else { return true; }
}