Hi, all. I try to debug the Text Interpreter to understand the program control flow. But I can not. I do it according to http://msdn.microsoft.com/en-us/library/bb146203(VS.80).aspx But at the 18 step "In Solution Explorer, right-click the TITest project and click Properties." I encounter a error. After click the Properties, A runtime error pop out.. VS: VS 2005 professional edition sp1 VS sdk: VS 2005 SDk 4 Os: xp sp2 -------------------runtime error infomation--------- Debug Assertion Failed Program:.... File:c:\program files\microsoft visual studio 8\vc\atlmfc\include \cstring.h Line:1395 Expression:__atl_condVal For infomation on how your program can cause an assertion failure, see the ........ ---------------------------------------- Is there anyone running into the problem.. -------- By the way, It seems that I encouter the error just as the following link description: http://www.bokebb.com/dev/english/1965/posts/196563848.shtml .........................................