function checkform(form)
{
if (form.first_name.value =="") 
{
   alert("Please Enter Your First Name.");
   form.first_name.focus(); 
   return false;
}
else if (form.last_name.value =="") 
{
   alert("Please Enter Your Last Name.");
   form.last_name.focus(); 
   return false;
}
else if (form.email.value =="") 
{
   alert("Please Enter Your EMail Address.");
   form.email.focus(); 
   return false;
}
else if (form.email.value.indexOf("@")<1 
   ||    form.email.value.indexOf(".")<1 )
{
   alert("Please Enter A Valid EMail Address.");
   form.email.focus(); 
   return false;
}
else if (form.phone.value =="") 
return true;
}