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

function hideDiv(objectId){		  
	  changeObjectVisibility(objectId,'hidden','none');
}
function showDiv(objectId){	 
	  changeObjectVisibility(objectId,'visible','block');
}