window.onload=function(){
	setImageReplace();
}

function setImageReplace(){
	
	var target_uls=["gnavi"];
	
	for(j=0;j<target_uls.length;j++){
		target_images=document.getElementById(target_uls[j]).getElementsByTagName('li');
		for(var i=0;i<target_images.length;i++){
			target_image=document.getElementById(target_uls[j]).getElementsByTagName('li')[i];
			if(target_image=target_image.getElementsByTagName('a')[0].getElementsByTagName('img')[0]){
				if(target_image.addEventListener){
						target_image.addEventListener('mouseover',imageon,false);
						target_image.addEventListener('mouseout',imageoff,false);
				}else if(target_image.attachEvent){
						target_image.attachEvent('onmouseover',imageon);
						target_image.attachEvent('onmouseout',imageoff);
				}
			}
		}
	}
	
		var target_btn=document.getElementById('textsize');
				if(target_btn.addEventListener){
						target_btn.addEventListener('click',changetext,false);
				}else if(target_btn.attachEvent){
						target_btn.attachEvent('onclick',changetext);
				}
}

function imageon(evt){
	if(evt.currentTarget){
		var imagename=evt.target.src;
		if(imagename.lastIndexOf("_on.gif")==-1){
			imagename=imagename.substr(0,imagename.lastIndexOf(".gif"));
			evt.target.src=imagename + "_on.gif";
		}
	}else if(window.event){
		var imagename=evt.srcElement.src;
		if(imagename.lastIndexOf("_on.gif")==-1){
			imagename=imagename.substr(0,imagename.lastIndexOf(".gif"));
			evt.srcElement.src=imagename + "_on.gif";
		}
	}
}

function imageoff(evt){
	if(evt.currentTarget){
		var imagename=evt.target.src;
		if(imagename.lastIndexOf("_on.gif")!=-1){
			imagename=imagename.substr(0,imagename.lastIndexOf("_on.gif"));
			evt.target.src=imagename + ".gif";
		}
	}else if(window.event){
		var imagename=evt.srcElement.src;
		if(imagename.lastIndexOf("_on.gif")!=-1){
			imagename=imagename.substr(0,imagename.lastIndexOf("_on.gif"));
			evt.srcElement.src=imagename + ".gif";
		}
	}
}

function changetext(evt){
	var changebtn=document.getElementById('textsize');
	var changebtnname=changebtn.src;
	if(changebtnname.lastIndexOf("large.gif")!=-1){
	document.getElementById('wrapper').style.fontSize="150%";
	document.getElementById('wrapper').style.lineHeight="150%";
	changebtnname=changebtnname.substr(0,changebtnname.lastIndexOf("large.gif"));
	document.getElementById('textsize').src=changebtnname + "small.gif";
	}else if(changebtnname.lastIndexOf("small.gif")!=-1){  
	document.getElementById('wrapper').style.fontSize="100%";
	document.getElementById('wrapper').style.lineHeight="150%";
	changebtnname=changebtnname.substr(0,changebtnname.lastIndexOf("small.gif"));
	document.getElementById('textsize').src=changebtnname + "large.gif";
	}
}