Hiding fields on the Report Page

I am having trouble hiding fields on the report page based on field value:

These are the examples that I have tried:

On 'Before Display' event page:

if ($values['Show Type'] == "Combined Test") {
$pageObject->hideField("XC Jump");
$pageObject->hideField("XC Time");
}

On Javascript onLoad event page:

var ctrl = Runner.getControl(pageid, 'Show Type');
if (ctrl.getValue()=='Combined Test'){
ctrl.hide('XC Time');
ctrl.hide('XC Jump');
};

but each time I build the project, those two fields still appear. Can anyone please help me?