function validate(mainform) {
mFNv=mainform.a1_FirstName.value;
mLNv=mainform.a2_LastName.value;
mEv=mainform.a3_Email.value;
mPv=mainform.a4_Phone.value;

if (mFNv=="") {
alert("Please enter your first name.");
mainform.a1_FirstName.focus();
return (false);
} 
if (mLNv=="") {
alert("Please enter your last name.");
mainform.a2_LastName.focus();
return (false);
} 
if (mEv.indexOf("@")==-1) {
alert("Please enter a valid email address.");
mainform.a3_Email.focus();
return (false);
} 
if (mPv=="") {
alert("Please enter your phone number.");
mainform.a4_Phone.focus();
return (false);
} 

}