function extend(name) {
	if (document.getElementById(name+'_txt').style.display == 'block') {		
		document.getElementById(name+'_txt').style.display = 'none';
		document.getElementById(name+'_img').src = 'image/plus.gif';
	}else{
		document.getElementById(name+'_txt').style.display = 'block';
		document.getElementById(name+'_img').src = 'image/minus.gif';
	}
	lyr=document.getElementById('lyr1');
	wndo=document.getElementById('wn1');
	wndo1.maxY=(lyr.offsetHeight-wndo.offsetHeight>0)?lyr.offsetHeight-wndo.offsetHeight:0;
}