How do I to move my game without windows frame?

In NW.JS there is the option to move the window, ("set x" and "set y") but I can't calculate a formula that is not strange to try to move the game by clicking and dragging a fixed sprite for example, where i can just click, hold and drag it to move the NWJS window.

My Attempt

Hi Dop, thanks for reply, I really liked the smoothness when moving, but moving minimally fast and the mouse leaving the window before the lerp is complete, it just stops moving, I thought it was a problem with my mouse, but noting well I identified this, I think we are on the right path.

Another observation I wanted to make is that I think I saw a similar formula a few months ago, but I can't find it anywhere and I didn't use lerp or round.

round is required, because window coordinated must be integer, otherwise you'll get an error and the window will not move.

Without lerp the window starts wobbling like crazy, I couldn't figure out why..

Okay, but if we move minimally fast and the mouse comes out of the window before the lerp is finished, it just stops moving, try move little faster, when button is down.