if(!walkSpeed){
	walkSpeed	= {};
	// interface
	walkSpeed.value = "normal";
	walkSpeed.change = function( settingName ){
		this.value = settingName;
		var newSettings = this[settingName];
		for(var nam in newSettings){
			walk_obj[nam] = newSettings[nam];
		}// for:  each affected setting
	}// change()
}// if:  walkSpeed doesn't exist

if(!walkSpeed.normal){
	walkSpeed.normal = {
		walkSpeed: 3,		// max speed  (pixels per frame)
		acel: 1.2,			// acelleration increment
		decel: 0.5			// brake multiplier
	}
}// if:  walkSpeed.normal doesn't exist