IE 8 crashes instead of opening debug dialog on encountering "_asm int 3;" in the dll code

I wanted to set breakpoint in the dll code so I introduced the statement "_asm int 3;". IE is supposed to open a dialog box saying that an unexpected exception has occured, and whether to c开发者_JAVA技巧lose or debug. But it simply cuts down the window. The dll is a _Debug version not _Release version. Another thing I noticed is that using the "debugger;" statement in the javascript code also causes the same behaviour - window dies without notice. Why is this happening?

JIT debugging might be disabled. In your Visual Studio options, under Debugging > Just-In-Time, check the Native and Script options.

As an aside, you should probably call DebugBreak() instead of issuing _asm int 3. It's clearer that way.