How to invoke Xclient?

[Chowdhury Takdir Hossain <takdir dblab is tsukuba ac jp>]

Hello

Can anyone tell me how to invoke a Xclient program from gtk+(1.0.6).
I tried in the following way. It complies but fail to launch the kterm
saying that "sh: command not found" 
menuitem = CreateMenuItem (menu, "Kterm", "", 
			       "Terminal emulator", 
			       GTK_SIGNAL_FUNC(system), "kterm &");

Am I doing any wrong here?