Actionscript v2. MX2004

How do i stop my man bumping into a wall? This is my script so far,

if (Key.isDown(Key.RIGHT)) {
play();
_x += movespeed;

man.hitTest(_x+1, _y, true){need script for not letting man move to right}

Please correct my script if it is wrong and if possible, provide me with the code for not letting man move to right. (The wall's instance name is "walls")