I'm having trouble validating my form for missing information. Tried many different functions but when submit the form it will reset the form or it will try to send it. I'm lost any help please....

I'm still new to JavaScript and I'm having trouble with an assignment. I can't seem to get my functions to work right for the alert to check for missing information when you submit the page and when...

function validate_required(field,alerttxt)
{
with (field)
{
if (value==null||value=="")
{
alert(alerttxt);return false;
}
else
{

Hi, I'm new to Javascript and I'm having trouble with my function to check for missing information in the code. Any ideas? Thanks