/**
* function getStyleObject(string) -> returns style object
*  given a string containing the id of an object
*  the function returns the stylesheet of that object
*  or false if it can't find a stylesheet.  Handles
*  cross-browser compatibility issues.
*/
function getStyleObject(objectId) {
	// cross-browser function to get an object's style object given its id
	if(document.getElementById && document.getElementById(objectId)) {
		// W3C DOM
		return document.getElementById(objectId).style;
	}else if (document.all && document.all(objectId)) {
		// MSIE 4 DOM
		return document.all(objectId).style;
	}else if (document.layers && document.layers[objectId]) {
		// NN 4 DOM.. note: this won't find nested layers
		return document.layers[objectId];
	}else {
		return false;
	}
}

/**
* changeObjectVisibility
*/
function changeObjectVisibility(objectId, newVisibility) {
	// get a reference to the cross-browser style object and make sure the object exists
	var styleObject = getStyleObject(objectId);
	if (styleObject) {
		styleObject.visibility = newVisibility;
		return true;
	}else {
		// we couldn't find the object, so we can't change its visibility
		return false;
	}
}


/**
* changeObjectDisplay
*/
function changeObjectDisplay(objectId, newDisplay) {
	// get a reference to the cross-browser style object and make sure the object exists
	var styleObject = getStyleObject(objectId);
	if (styleObject) {
		styleObject.display = newDisplay;
		return true;
	}else {
		// we couldn't find the object, so we can't change its visibility
		return false;
	}
}

/**
* changeObjectDisplay
*/
function switchObjectDisplay(objectId) {
	// get a reference to the cross-browser style object and make sure the object exists
	var styleObject = getStyleObject(objectId);
	if (styleObject) {
		if(styleObject.display==""){
			return changeObjectDisplay(objectId,"none");
		}
		else{
			return changeObjectDisplay(objectId,"");
		}
	}else {
		// we couldn't find the object, so we can't change its visibility
		return false;
	}
}

function undisplayBrothers(objectId){
	var son=MM_findObj(objectId);
	var brothers=son.parentNode.childNodes;
	
	for(i=0;i<brothers.length;i++){
		if(brothers[i].id!=null){
			changeObjectDisplay(brothers[i].id,"none");
		}
	}
}


/**
*
*/
function moveObject(objectId, newXCoordinate, newYCoordinate) {
	// get a reference to the cross-browser style object and make sure the object exists
	var styleObject = getStyleObject(objectId);
	if (styleObject) {
		styleObject.left = newXCoordinate;
		styleObject.top = newYCoordinate;
		return true;
	}else {
		// we couldn't find the object, so we can't very well move it
		return false;
	}
}