帮忙看一下这个程序哪里有错，谢谢

zeeway

1. 
   
2. #include <X11/Intrinsic.h>
   
3. #include <stdio.h>
   
4. Window FindWindow(Display* pDisplay, Window start, char* name)
   
5. {
   
6.   Status stat;
   
7.   int i,num;
   
8.   Window w,root,parent;
   
9.   Window* children = NULL;
   
10.   char* title;
    
11.   if(XFetchName(pDisplay, start, &title) == 1)
    
12.   {
    
13.     if (strcmp(name, title)==0)
    
14.     {
    
15.       XFree(title);
    
16.       return start;
    
17.     }
    
18.     XFree(title);
    
19.   }
    
20.   stat = XQueryTree(pDisplay, start, &root, &parent, &children, &num);
    
21.   if (stat == 1)
    
22.   {
    
23.     /* search each child window for a match: */
    
24.     for (i = num; i > 0; i--)
    
25.     {
    
26.       if (XFetchName(pDisplay, start, &title )==1)
    
27.       {
    
28.         if (strcmp(name, title)==0)
    
29.         {
    
30.           /*found it*/
    
31.           XFree(title);
    
32.           return start;
    
33.         }
    
34.         XFree(title);
    
35.       }
    
36.     }
    
37.     /*search the descendents of each child for a match:*/
    
38.     for (i = num; i > 0; i--)
    
39.     {
    
40.       w == FindWindow(pDisplay, children[i], name);
    
41.       if (w != 0)
    
42.       {
    
43.         XFree(children);
    
44.         return w;
    
45.       }
    
46.     }
    
47.     if (children != NULL)
    
48.     {
    
49.       XFree(children);
    
50.     }
    
51.   }
    
52.   return 0;
    
53. }
    
54. int main(int argc, char* argv[])
    
55. {
    
56. //  Widget toplevel = XtInitialize(argv[0], "Get_URL", NULL, 0, &argc, argv);
    
57. //  Display *dpy = XtDisplay(toplevel);
    
58.   Display *dpy = XOpenDisplay(0);
    
59.   FindWindow(dpy,DefaultRootWindow(dpy),"rdesktop");
    
60.   return 1;
    
61. }
    
62.    

复制代码

这个程序是我用来找rdesktop窗口的，编译运行后出现如下错误：
X Error of failed request:  BadWindow (invalid Window parameter)
  Major opcode of failed request:  20 (X_GetProperty)
  Resource id in failed request:  0x211
  Serial number of failed request:  682
  Current serial number in output stream:  682
应该怎么改啊？