function getParentWithProperty( findThisVariable ){
	var output_mc = this._parent || _parent;		// start with the _parent of whatever object called this function,  fallback to the original movieClip containing this function
	
	while( isFound(output_mc) !== true  &&  output_mc._parent !== undefined){
		output_mc = output_mc._parent;
	}// loop:  search upward for a textbox
	if( isFound(output_mc) !== true ){
		output_mc = null;
	}// if:  no textbox was found, then use NULL
	return output_mc;
	
	function isFound( mc ){
		return Boolean(  mc[ findThisVariable ]  !==  undefined  );		// variable exists => true,  undefined => false
	}// isFound()
} // getParentWithProperty()