// JavaScript Document
//for IE6 IE7 Fire Fox2
function dk_showHideById(idName , cmd){
	if(!idName){
		alert('need a id name in one of HTML elements.');
		return;
	}
	
	var idObj = dk_findObj(idName);
	if(!idObj){
		alert('error!! no object name is ' + idName + ' in this HTML document.');
		return;
	}
	
	if(cmd == 'show' || cmd == 'hide'){
		dk_doShowHide(idObj , cmd);
	} else {
		alert('aneed one more argument [\'show\' or \'hide\'].');
		return;
	}
	
	
}
function dk_findObj(idName){
	var idObj = document.getElementById(idName);
	return idObj;
}
function dk_doShowHide(idObj , cmd){
	if(cmd == 'show'){
		idObj.style.display = '';
	} else if(cmd == 'hide'){
		idObj.style.display = 'none';
	}
}