pop up for a program error

 Hi All,

 I want to build a program which has a user alert facility as soon as it find some error while executing. For example if there is a program like this  

procedure(testing()

a = "try"

b = 2

c=a*b

)  This program will find an error at line c = a*b. and throw a *ERROR ..... message in icfb.log. I want to have a pop up window which alert the user as soon as it exit. I am using a try1=errset(testing) now. According to try1 value , (t or nil) i can find if the program executed or not. but it will suppress the error message in ICFB.log

 Thank You,