You could also just use your own script putting an alert at the bottom 
with a return true like this

function formCheck()
    {
        if (document.contactform.first_name.value =3D=3D "")
        {
        alert("First Name | Problem:\n\nYou forgot to enter\nyour first
name\n\nPlease enter it\n\nThis entry is required!.");
        return true;
        }
	=09
		if (document.contactform.last_name.value =3D=3D "")
        {
        alert("Last Name | Problem:\n\nYou forgot to enter\nyour last name\
n\nPlease
enter it\n\nThis entry is required!.");
        return false;
        }
	=09
		if (document.contactform.phone_area.value =3D=3D "")
        {
        alert("Telephone # Area Code | Problem:\n\nYou forgot to enter\
nyour area
code\n\nPlease enter it\n\nThis entry is required!.");
        return false;
        }
	=09
		if (document.contactform.phone2.value =3D=3D "")
        {
        alert("Telephone # 1st Digits | Problem:\n\nYou forgot to enter\
nyour 1st
digits\n\nPlease enter it\n\nThis entry is required!.");
        return false;
        }
			=09
		if (document.contactform.phone3.value =3D=3D "")
        {
        alert("Telephone # 2nd Digits | Problem:\n\nYou forgot to enter\
nyour 2nd
digits\n\nPlease enter it\n\nThis entry is required!.");
        return false;
        }
	=09
		if (document.contactform.contact_time.selectedIndex =3D=3D 0)
		{
		alert("Contact Time | Problem:\n\nYou forgot to enter\nyour contact
time\n\nPlease enter it\n\nThis entry is required!.");
		return false;
		}=09
			=09
		if (document.contactform.submit_by.value.indexOf("@") =3D=3D -1 ||
        document.contactform.submit_by.value =3D=3D "")
        {
        alert("Email Address | Problem:\n\nYou forgot to enter\nyour email\
n\nPlease
enter it\n\nThis entry is required!.");
        return false;
        }
					=09
		if (document.contactform.street_address.value =3D=3D "")
        {
        alert("Street Address | Problem:\n\nYou forgot to enter\nyour
address\n\nPlease enter it\n\nThis entry is required!.");
        return false;
        }
	  
	   	if (document.contactform.city.value =3D=3D "")
        {
        alert("City | Problem:\n\nYou forgot to enter\nyour city\n\nPlease 
enter
it\n\nThis entry is required!.");
        return false;
        }
	=09
		if (document.contactform.state.selectedIndex =3D=3D 0)
		{
		alert("State | Problem:\n\nYou forgot to enter\nyour state\n\nPlease 
enter
it\n\nThis entry is required!.");
		return false;
        }
					=09
		if (document.contactform.zip_code.value =3D=3D "")
        {
        alert("Zip Code | Problem:\n\nYou forgot to enter\nyour zip code\n\
nPlease
enter it\n\nThis entry is required!.");
        return false;
        }

     alert("all is ok");
     return true;

   }

but you must be sure that if you have an error you return FALSE within 
your checks, then the alert wont fire at the bottom.

hope this helps also :)