hi Alert message is not displaying.

In my flex application after some iteration in a page the alert messages not displaying but those are executed.In case for not putting any alert message after some iterations that page is not working it means if i click on any option in my page it is not working.Please give suggestion why it is happening like that.

The iterations like in my combo box change the number of pages from 50 to 100,100 to 200 then 200-50 and at one point of time my page is not working.

Thank You.