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

function btn_over(){
	if(document.getElementById('btn_submit')){
	var target_btn=document.getElementById('btn_submit');
	if(target_btn.addEventListener){
	target_btn.addEventListener('mouseover',onimg01,false);
	target_btn.addEventListener('mouseout',offimg01,false);
	}else if(target_btn.attachEvent){
	target_btn.attachEvent('onmouseover',onimg01);
	target_btn.attachEvent('onmouseout',offimg01);
	}
	}
	
	if(document.getElementById('btn_back')){
	var target_btn=document.getElementById('btn_back');
	if(target_btn.addEventListener){
	target_btn.addEventListener('mouseover',onimg02,false);
	target_btn.addEventListener('mouseout',offimg02,false);
	}else if(target_btn.attachEvent){
	target_btn.attachEvent('onmouseover',onimg02);
	target_btn.attachEvent('onmouseout',offimg02);
	}
	}
	
	if(document.getElementById('btn_send')){
	var target_btn=document.getElementById('btn_send');
	if(target_btn.addEventListener){
	target_btn.addEventListener('mouseover',onimg03,false);
	target_btn.addEventListener('mouseout',offimg03,false);
	}else if(target_btn.attachEvent){
	target_btn.attachEvent('onmouseover',onimg03);
	target_btn.attachEvent('onmouseout',offimg03);
	}
	}

}

function onimg01(evt){
	document.getElementById('btn_submit').setAttribute('src','images/cmn_btn_submit_on.gif');
}

function offimg01(evt){
	document.getElementById('btn_submit').setAttribute('src','images/cmn_btn_submit.gif');
}


function onimg02(evt){
	document.getElementById('btn_back').setAttribute('src','images/cmn_btn_back_on.gif');
}

function offimg02(evt){
	document.getElementById('btn_back').setAttribute('src','images/cmn_btn_back.gif');
}

function onimg03(evt){
	document.getElementById('btn_send').setAttribute('src','images/cmn_btn_send_on.gif');
}

function offimg03(evt){
	document.getElementById('btn_send').setAttribute('src','images/cmn_btn_send.gif');
}