<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><title>无标题文档</title><script language="javascript" >...function moveOpR()...{ var os=document.getElementById("s"); var os2=document.getElementById("s2"); if(os.options.length>=1)...{ var txt=os.options[os.options.selectedIndex].text; var val=os.options[os.options.selectedIndex].value; var op=new Option(txt,val,true,true); os2.options.add(op); os.remove(os.options.selectedIndex); }}function moveOpL()...{ var os=document.getElementById("s"); var os2=document.getElementById("s2"); if(os2.options.length>=1)...{ var txt=os2.options[os2.options.selectedIndex].text; var val=os2.options[os2.options.selectedIndex].value; var op=new Option(txt,val,true,true); os.options.add(op);//[os2.options.length]=op; os2.remove(os2.options.selectedIndex); } }</script></head><body > <select name="s" size="4" id="s" ondblclick="moveOpR()" > <option>1 </option><option>2 </option><option>3 </option><option>4 </option><option>5 </option><option>6 </option> </select> <select name="s2" size="4" id="s2" ondblclick="moveOpL()"> <option>7 </option> <option>8 </option> <option>9 </option> <option>10 </option> <option>11 </option> <option>12 </option> </select></body></html>