How do I check with a Bash script if an application is running?

I have a gnome-run application in my home folder. I have now added the application to run when I press Meta+R (I added it in in CCSM ). I run the application by executing

./gnome-run

in my home folder.
I can't find any trace of the application process in the output of

-A

. The problem is that if I have the gnome-run program open and I press the key combination I want the application to close. Is there a way to create a bash file that checks if the applications is running? If it is then close it, else launch it.