function validate(emailad) 
{
var exclude=/[^@\-\.\w]|^[_@\.\-]|[\._\-]{2}|[@\.]{2}|(@)[^@]*\1/;
var check=/@[\w\-]+\./;
var checkend=/\.[a-zA-Z]{2,4}$/;
if(((emailad.search(exclude) != -1)||(emailad.search(check)) == -1)||(emailad.search(checkend) == -1)){
alert("error in email address");
return (false);
}
}

function validform(pform)
{

if (pform.firstname.value == "")
{
alert("insert firstname");
pform.firstname.focus();
return false;
}
if (pform.lastname.value == "")
{
alert("insert lastname !");
pform.lastname.focus();
return false;
}
if (pform.email.value == "")
{
alert("insert email !");
pform.email.focus();
return false;
}
if (pform.company.value == "")
{
alert("insert company !");
pform.company.focus();
return false;
}
if (pform.email.value)
{
return (validate(pform.email.value));
}

}