方法一
FUNCTION boolean ShowWindow( ulong winhandle,& int wincommand ) Library "user32"  
FUNCTION boolean BringWindowToTop( ulong HWND )& Library "user32"  
FUNCTION long FindWindowA( ulong Winhandle, & string wintitle ) Library "user32"  
创建一个窗口’w_test’ . 将title 设置为"Test Window".  
在application的 Open 事件中加入如下代码:  
long ll_winhandle 
ll_winhandle = FindWindowA( 0, "Test Window" )  
If ll_winhandle > 0 Then  
BringWindowToTop( ll_winhandle )  
ShowWindow( ll_winhandle , 5 )  
Return  
End If  
Open( w_test )  

方法2
function ulong CreateMutexA (ulong lpMutexAttributes, int bInitialOwner, ref string lpName) library ″kernel32.dll″
　　function ulong GetLastError () library ″kernel32.dll″
　　然后在application的 Open 事件中加入如下代码:
　　ulong ll_mutex, ll_err
　　string ls_mutex_name
　　if handle (GetApplication (), false) <> 0 then
　　ls_mutex_name = this.AppName ＋ char (0)
　　ll_mute