Question

Is this valid jQuery? Or have I mixed it up with regular JavaScript too much? In any case it is not working (I would expect it to print “testing” between the appropriate tags):

<script type="text/javascript">
  var testing = "testing";
  testIt=function() {
    $('#cont').html(testing);
  }
</script>

to be invoked when:

<input TYPE="button" NAME="button4" Value="Write" onClick="testIt()">

obviously there is a:

<div id="cont"> </div>

in the html.

Answer 1

No, that’s not “mixing jQuery and Javascript” too much. jQuery is Javascript. You won’t ever have to worry about mixing them.

I can’t reproduce your problem. Your code seems to be working fine. See it in this demo.

That said, I think you should use a method that is more idiomatic to jQuery instead of mixing Javascript with the markup.

I would recommend changing the NAME attribute

NAME="button4"

to an id attribute:

id="button4

and using this jQuery:

var testing = "testing"; 
$("#button4").click(function(){
  $("#cont").html(testing); 
});