Help with the actionscript please

hi
I have made button that when you click it a pop up window appear.
but I don’t know how to put text in the body in that pop up window(there is already text in the title of the window).

could you please tell me what action script I should add to my button action.
below is the actionscript the button has now.but when I click it you can see what appear on the picture below.Please help me.

`thank you in advanced

on (release) {
_root.scrHEIGHT=100
_root.scroller.scroller.gotoAndStop(2);
_root.scroller._x = 100;
_root.scroller._y = 150.7;
_root.TM_title = “EXHIBITIONS”;
_root.READ = 2;
}