Simple Form Validation

Hi guys,

Im doin a simple form @ the moment from kirupa’s tut’s http://www.kirupa.com/developer/actionscript/flash_php_email.htm,
I need to validate all the fields! I have tryed searching the net for some help with this but all the examples Are like 3 paragraphs long and do not understand ithem @ all!!!

Can someone please heap and shine some light on this issue, so that a beginner like me can understand whats actually happening.

Thanx.