You need to create a reference to the form. There are a number of ways to do that. I like to create a class that holds all form references as properties and access the functionality through the reference. Then your form reference class can have a do form method that registers the form. Then you can access the methods like: oRefObject.mymainform.load()

There are a number of different techniques so just pick the one you like after everyone gives you their respective opinion. :)