MessageBox - c-script and vbs-script problem

hi Everybody,
firstly i prefer to use C-script in my project.

in the my wincc project, i want to use script language. when i use the VBS language there is no problem. when i use the c-script there is problem. The problem is that, if youpress the push button on the screen, the MessageBoxmust be shown on the screen and this Message Box has to be in front of the Main Screen.But Message Box shows behind of Main Screen. And the userssee the nothing on screen. i will put the C-SCRIPTand VBS-SCRIPT.

what is the problem , please help me.
--------------------------------------------------------------------------------------------------------------------------------------
C-SCRIPT CODE

#include "apdefap.h"
void Click(char* lpszPictureName, char* lpszObjectName )
{
int i;
i=MessageBox(NULL,"CIKMAK ISTEDIGINIZDEN EMINMISINIZ?","CIKIS",MB_OKCANCEL);
if (i==1) DeactivateRTProject ();
}

--------------------------------------------------------------------------------------------------------------------------------------
VBS-SCRIPT CODE

Sub Click(ByVal Item)

Dim XX
XX=MsgBox ("CIKMAK ISTEDIGINIZDEN EMINMISINIZ",vbOKCancel,"CIKIS")
If XX=1 Then
HMIRuntime.Stop
End If

End Sub

Hi:
Try this.
i = MessageBox(hWnd,"Start the Motor1?","Parameter",
MB_YESNO|MB_ICONQUESTION|MB_SYSTEMMODAL);

Best regards

Buzz LightYear
ANPRO Automation Co. , Ltd
TEL：+886-2-29995926
FAX：+886-2-29995929
Mobile Phone：+886-932018640
E-Mail Address： <mailto:vincentchang@anpro.com.tw>
5F/9,NO.14,Lane 609,Sec.5,Chung Hsin Rd,
San Chung City,Taipei County,Taiwan,R.O.C

Mr. Buzz LightYear
thanks for your helps. I have tried to put MB_SYSTEMMODAL end of the my program. And the result is OKEY.

Best regards.