CI and ExtJS

[eluser]mistress_shiira[/eluser]
good day guys!
im practicing incorporating extjs with CI.
but im stuck with this:
for example, i have a simple form that ive built using extjs...
supposedly you have an event handler for the form when you click on the submit button.
so i created an event handler,but im stuck as to how im going to tell it to go to a controller function of mine that would check for validation errors.

any ideas how to?would greatly appreciate it.