在下拉框中输入文字
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><html><head><title></title><meta name="GENERATOR" content="Microsoft Visual Studio .NET 7.1"><meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"></head><body><script language=javascript >function catch_keydown(sel) { switch(event.keyCode) { case 13: //Enter; sel.options[sel.length] = new Option("","",false,true); event.returnValue = false; break; case 27: //Esc; alert("text:" + sel.options[sel.selectedIndex].text + ", value:" + sel.options[sel.selectedIndex].value + ";"); event.returnValue = false; break; case 46: //Delete; if(confirm("刪除當前內容!?")) { sel.options[sel.selectedIndex] = null; if(sel.length>0) { sel.options[0].selected = true; } } event.returnValue = false; break; case 8: //Back Space; var s = sel.options[sel.selectedIndex].text; sel.options[sel.selectedIndex].text = s.substr(0,s.length-1); event.returnValue = false; break; } } function catch_press(sel) { sel.options[sel.selectedIndex].text = sel.options[sel.selectedIndex].text + String.fromCharCode(event.keyCode); event.returnValue = false; } </script><select onkeydown="catch_keydown(this);" onkeypress="catch_press(this);"><option>a</option><option>b</option></select></body></html>