Visual C++ :: How To Add A Limit On Size

Im working on a small code and am trying to limit the size of the mysql databse string its pulling.

It can only be 119 characters, or less if its more i would like to do nothing, but if its meets the requirements it runs the script.

Code:
int32 message_id;
string_t message ="Is requesting some one to respond.";<_______________TEMP SHOULD BE THE POSTERS MESSAGE
string_t username = "Guest";<_______________TEMP SHOULD BE THE POSTERS NAME
// char will not be logged in so get the id manually

[Code] ....

So here is where I'm heaving the problem

if(message is less then 119 characters run script )<<___________THIS IS THE CODE LINE IM TRYING TO LEARN
{
char buf[110];
sprintf(buf,"[Web Chat] %s %s",username.c_str(), message.c_str());

[code].....