Disable / enable submit button prior to filling everything out?

So I have a few inputs that the user must fill out before they can submit. How can this be done with the following text input and select element?

<input id="project_input" type="text" name="peer_project" onclick="this.value='';" onmousemove="enable_submit();" value="What project was this?" />
<select name="peer_group"><option value="What group did you belong to?">What group did you belong to?</option><option value="group_1">Group 1</option><option value="group_2">Group 2</option></select>

I had some JavaScript that I was working on for the “enable_submit()” function in the above text-box, but as can be expected, it didn’t work. It would activate the submit upon mouseover regardless of what was in the input at that moment. I would love to know what I did wrong with it (see below):

function enable_submit(){
	if((document.getElementById("project_input").value != 'What project was this?') || (document.getElementById("project_input").value != '')){
		document.getElementById("submit").disabled = false;

You are testing if either the field is something other than “What project is this?” or is something other than “”. The only time that isn’t true is when the field contains both values at the same time and since it can only have one value at a time the condition you are testing for can never happen. You need && in place of the ||

You should also use JavaScript to disable the submit button in the first place so that when JavaScript is disabled that it is still possible to submit the form.

Stephen, you rock. :.)

But I swore I tried that… Oh well, it’s working now! Thanks!

One more question: what if I have a bunch of inputs to check against? What would you advise as being the most efficient way to check them? Just add all of their conditions to the IF clause???

I would do it as separate if statements so that you can tell the person which field(s) need to be corrected.