Custom Code on 'View Form'

Hello

I am new to netsuite. I looked at the developer guide but have probably missed a basic point in it.

I uploaded the following client script against the Case Edit Form.

function simple(type) {
    alert('simple start');
    alert(type);
}

When I edit a case I get the expected messages, but how do I get the code to run when I view a case?

Maybe I should explain a little further - I would like to add a tab to the view form and include some html to show information from an external database, so I need to know how to get a reference to the current form so I can call the addSubTab function.