function switchTabs(tab){
	
}
function tabNav(which){
	var htmlStr = '';
	if(which == 'dwgtab' || which == ''){
		htmlStr += 'DWG';
	}else{
		htmlStr += '<a href="javascript:void(0);" onMouseDown="tabNav(\'dwgtab\')">DWG</a>';
	}
	htmlStr += ' | ';
	if(which == 'dxftab'){
		htmlStr += 'DXF';
	}else{
		htmlStr += '<a href="javascript:void(0);" onMouseDown="tabNav(\'dxftab\')">DXF</a>';
	}	
	
	htmlStr += '';
	htmlStr += '';
	htmlStr += '';
	document.getElementById('switchTabNav').innerHTML = htmlStr;
	
	clearTabNav();
	
	if(which == ''){
		document.getElementById('dwgtab').style.display = 'block';
	}else{
		document.getElementById(which).style.display = 'block';
	}
	reDrawSifr();
}
function clearTabNav(){
	document.getElementById('dwgtab').style.display = 'none';
	document.getElementById('dxftab').style.display = 'none';
}