can some one tell me what is going wrong with this

can some one tell me what is going wrong with this, it's a form validation with allert type text boxes that appear w/ the appropriate text when the feilds are left empty.


on (release) {
if (f1 eq "") {
mes_box.gotoAndPlay(2);
mes_box.title = "Name";
mes_box.error = "Please type your name in the feild provided";
mes_box.closer = "<close window";
} else if (f4 eq "") {
mes_box.gotoAndPlay(2);
mes_box.title = "Message Box";
mes_box.error = "Please give us a detailed message in the provided area.";
mes_box.closer = "<close window";
} else {
loadVariablesNum("contact.php", 0);
gotoAndPlay(4);
}
}