Contact Form Alert Text

So my contact form likes to send everything out even if the whole form isn't filled out, why isn't the alert working. Here's my script.

submit_mc._alpha = 40;
formCheck = new Object();
formCheck.onKeyUp = function ()
{
if (name_txt.text != "" && email_txt.text != "" && subject_txt.text != "" && number_txt.text != "" && ymm_txt.text != "" && miles_txt.text != "" && app_txt.text != "" && timee_txt.text != "" && datee_txt.text != "" && msg_txt.text != "")
{
alert_txt.text = "";
submit_mc._alpha = 100;
}
else
{
submit_mc._alpha = 40;
} // end else if
};
Key.addListener(formCheck);
normal_border = 0;
focus_border = 255;
normal_background = 16777215;
focus_background = 16776960;
normal_color = 0;
focus_color = 0;
inputs = [name_txt, email_txt, subject_txt, number_txt, ymm_txt, miles_txt, app_txt, timee_txt, datee_txt, msg_txt];
for (var elem in inputs)
{
inputs[elem].border = true;
inputs[elem].borderColor = normal_border;
inputs[elem].background = true;
inputs[elem].backgroundColor = normal_background;
inputs[elem].textColor = normal_color;
} // end of for...in
TextField.prototype.onSetFocus = function ()
{
this.borderColor = focus_border;
this.backgroundColor = focus_background;
this.textColor = focus_color;
};
TextField.prototype.onKillFocus = function ()
{
this.borderColor = normal_border;
this.backgroundColor = normal_background;
this.textColor = normal_color;
};
Selection.setFocus(subject_txt);
dataSender = new LoadVars();
dataReceiver = new LoadVars();
submit_mc.onRelease = function ()
{
if (name_txt.text != "" && email_txt.text != "" && subject_txt.text != "" && number_txt.text != "" && ymm_txt.text != "" && miles_txt.text != "" && app_txt.text != "" && timee_txt.text != "" && datee_txt.text != "" && msg_txt.text != "")
{
alert_txt.text = "Please complete all forms.";
_root.play();
dataSender.name = name_txt.text;
dataSender.email = email_txt.text;
dataSender.subject = subject_txt.text;
dataSender.number = number_txt.text;
dataSender.ymm = ymm_txt.text;
dataSender.miles = miles_txt.text;
dataSender.app = app_txt.text;
dataSender.timee = timee_txt.text;
dataSender.datee = datee_txt.text;
dataSender.msg = msg_txt.text;
dataReceiver.onLoad = function ()
{
if (this.response == "invalid")
{
_root.gotoAndStop(1);
alert_txt.text = "Please check email address - does not appear valid.";
}
else if (this.response == "error")
{
_root.gotoAndStop(3);
}
else if (this.response == "passed")
{
_root.gotoAndStop(2);
} // end else if
};
dataSender.sendAndLoad("processEmail.php", dataReceiver, "POST");
}
else
{
alert_txt.text = "Please complete all fields before submitting form.";
} // end else if
};
stop ();