# Uncomment the Function and Add Code

Once the program name to be extended (for example, `payPlanMainPlanPage`) and the template to use (for example, `tabPage2.xsl`) are known, the associated template jsp file can be copied from the web application source's`` `/cm_templates` directory to the `/cm` directory and renamed to have the form `ext_XXXX.jsp`, where `XXXX` is the name of the program to be extended.

For example, in this case the jsp user exit template `./cm_examples/tabPageExit.jsp` would be copied and renamed to `./cm/ext_payPlanMaintPlanPage.jsp`. The following coding change inside the `extPostOnWindowLoad()` function would then be made for the modified behavior.

    	function extPostOnWindowLoad(){
    	//This should be used to set values/attributes when the page loads.
    	//This includes actions after a default.
    	//This function is called AFTER SPL's internal functions are called

    	protectField("START_DT");
    	alert ("Start Date Field is disabled. Defaulted to Current Date.");

    	}

Parent topic: Create an External User Exit