Need help placing towers around area for tower defence

Im currently working on a tower defense game and Im wondering how do I make it so that i can click on the towers in a GUI and then place them some where on the field

I currently have 3 towers

The towers already shoot the enemies and the enemies do follow a path

But I just don't know how to place towers about

*bump*

Can someone please help me its really important

Anybody???

Please I really need help

Check out this tower defense tutorial, which might help you: http://community.stencyl.com/index.php/topic,9984.0.html

Ive been using that tower defense tutorial But I want to be able to just place the towers like a normal tower defense game

As in locking into a grid, or making it so that the towers can be placed anywhere?