onChange client script defined on a MRVS is not working as expected

[sauravsumankumar]

function onChange(control, oldValue, newValue, isLoading) { if (isLoading || newValue == '') { return; }

var project = g_form.getReference('project_name', populateProjectNumber); 

}

function populateProjectNumber(project) { g_form.setValue('project_number', project.u_project_number); }