Ubuntu :: How To Make Gmrun For Windows+r

I want to launch 'gmrun' with the key combination of Windows+r(like how we launch run dialog box in windows)..but i am not able to do..

Here i am attaching the screen shots of what i am doing..

1) Launched Keyboard shortcuts application

2) Click on Add button

3) Entered name as 'gmrun'

4) command as 'gmrun' (because i am able to launch gmrun from terminal by just entering 'gmrun')

Here is the screenshot of what i have done so far. [URL]

5) Clicked on Apply button

6) Then i selected the gmrun action and entered 'Windows+r'

Here is the screenshot: [URL]

Still, I am not able to launch gmrun using Windows+r key combination.