Hi JD,

Please try the below updated code, It should work now.

var openby = g_form.getValue('opened_by');
	var resolveby = g_form.getValue('resolved_by');
	
	if(resolveby == openby)
		{
		g_form.setValue('u_firstcallresolution',true);
		g_form.setReadOnly('u_firstcallresolution',true);
		
	}

Kindly mark my answer as Correct and Helpful based on the Impact.

Regards,

Chaitanya