First let me explain something regarding the relationship between Lead, Person and Address. I am talking about Lead Summary Screen. When we click on the Add or Find this Person button which is available below the Lead Contact Details Screen, the screen that appears is the Person Entry Screen. Here in this screen an information regarding Person, Address, Phone/Email automatically populates from the Lead Screen. Please, refer the below screen shot.
Now suppose if some customization is done on the Person Entry screen and for that purpose a onload script is written on the Custom content box. Well, this works well everywhere the Person entry screen is used, but it does affect the functionality which is mentioned above. This is the case when we write an onload event script as follows.
Instead of this what we can do is, we can change the method to fire an event. that is, instead of using “for=window event=onload” we can use “window.attachEvent” as shown in below example.
(Note: Click an image to enlarge the same)