function validate() {
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.');
event.returnValue=false;
}
if (mLNv=='') {
alert('Please enter your last name.');
event.returnValue=false;
}
if (mEv.indexOf("@")==-1) {
alert('Please enter a valid email address.');
event.returnValue=false;
}
if (mPv=='') {
alert('Please enter your phone number.');
event.returnValue=false;
}

}