Javascript virtual joystick for touchscreen tablets which use wekbit as browser?

Hey there, i am developing a little game example based on html & javascript.

Question is:

Does anybody knows about some javascript virtual joystick asset?

or:

what would be a good approach to code it as simple as possible?

this is for a very basic maze game

i need the joystick to fire my up(), down(), left(), right() functions.

Solution must开发者_JAVA百科 be exclusively based on javascript, since this targets some android tablet which doesn't support flash.

Thanks in advance for your time.

The very easiest solution would be to just create 4 buttons/links, firing direction functions.