resizable window

I'm using NSIS to make a little app that's not an installer. Is there any way to have the window resizable by the user (can drag a corner of the window to make it bigger/smaller)?

I plan on using Resource Hacker to make my custom UI. Is there a way within it to make the UI resizable, or would it be a change to the NSIS source?

Thanks

Found the answer: WS_THICKFRAME