<div id="login_1_3a">
<a onfocus=this.blur() href="javascript:void(0)" class="l-button" style="width:80px" onclick='log_1()'>
<img onfocus=this.blur() id="img_a" border=0 align="middle" src="login_image/a_1.jpg" alt="沒有圖片！"> </img>
</a>
</div>

$("#img_a").attr("src", "login_image/b_2.jpg");

onfocus=this.blur()