[klaush]

Here we are:

function validateForm_question()
{
if(document.forms["question"].title.value.length == 0) {
alert('You need to enter a title for your Question.');
return false;
}
if(document.forms["question"].categoryid != undefined){
if(!isNaN(document.forms["question"].categoryid.value) == 0) {
alert('Category id must be a number.');
return false;
}else if(document.forms["question"].categoryid.value ==0){
alert("Please Select a Category.");
return false;
}
}
if(document.forms["question"].categoryid != undefined){
if(document.forms["question"].type.value == 0){
alert("");
return false;
}
}
return true;
}

And you can choose "Please choose a category".