Question

I have a form in my content page for which I am doing some client side validations via Javascript. The Javascript behaves as expected if I place the JS code directly in the content page. But if I place the JS code in it’s own file and try accessing that from the content/master page (through the script tag’s src attribute), I get a run time error when the validation function in JS being called.

To be specific, I get the below error.
Microsoft JScript runtime error: Objected expected/required at this line – document.getElementById(‘<%=txtemailId.ClientID %>’).value

txtemailId is in the content page.

Javascript code is placed in validation.js and accessed via master page.

The reason I guess is that when .net is parsing the files, it is unable to substitute txtemailId.ClientID with the client side value that would be generated later on. So, how should one go about it? Thanks!

Answer 1

The answer to this is quite simple.

Within your content page declare an in-line JScript variable, make sure this is above your tag.

<script>
  var emailClientId = &lt;%=txtemailId.ClientID%&gt;;
</script>

Within your include.js file make use of the globally scoped emailClientId variable.

Obviously this is a bit clumsy because not all of the JScript code is contained within the include.js file, which makes it difficult to debug / diagnose as it is not clear specifically where the value is coming from. You should clearly comment / document this within your code to make maintenance of he codebase easier in the future.