Disabling a list box?

[Solarpitch]

Hi there,

 

I am basically looking to disable a list box based on the value of a text field above it. I only want to enable the list box if a user has entered something into the textfield, so as soon as the textfield contains data the list box will be enabled.

 

Just looking for some help as i have tried and tried Google to no joy.

 

Thanks

[phpQuestioner]

<script language="javascript">
function onlyAllow()
{
var exact = document.getElementById('myfield').value;
if (exact == "hello")
{
document.getElementById('myselector').disabled = false;
}
else 
{
alert("Wrong Entry!");
document.getElementById('myselector').disabled = true;
}
}
</script>

<input type="text" id="myfield" onblur="onlyAllow()">

<select id="myselector" disabled>
<option selected>Choose One
<option value="1">1
<option value="2">2
<option value="3">3
</select>

 

PS: I guess a select menu is what you meant by a list; so that is the way I coded it in the example.