Key down to play symbol question

I am trying to move  a character when they have a button being pressed. This works but the issue I am having is that it does not loop for me. As soon as that cycle is done it stops dead.

Here is my code on creation complete

var myChar = sym.getSymbol("character");

//

$(document).keydown(function(e){

          if (e.keyCode == 37) {

                         myChar.play("running");

                         return false;

          }

});

and then at the end of the running cycle I have this

sym.play('running');

This works well when I press and release the button but if I hold down left key it stops at the end of the animation.