Simple running script?

I'm looking for a simple "press and hold B to run" type script. So whenever you press and hold the back button (forget which one it is) you'll move faster.

Please?

This can be done with common events. Make a common event run on a switch, parallel process, with this move event:

IF Key (put key here) is preessed:
  Change move speed to whatever
else
  Change speed to w/e
end

But does that stay on for however long you keep the button pressed?

I think it does, if its a common event (I know, necro-posting.... *sighs* but i have a question) If I were to do this, and along with putting the change speed, a change in chara sprite, could I give my chars a seperate running sprite?  And urm, is there a similare way to jump, I can't find a predescribed button for jumping, but I know its a possible movement.... just not how to do it, and how effective it is.... thanks

Edit:  *sheepish* never mind, i figured it out......  Thanks though, ha, it got me thinking on the right track

Haha, k. Oh, for anyone who uses this in the future: Turn off the triggering switch when you're talking if your button for running is the C button. The one like Enter and Spacebar.