Use js to implement an editable select drop down list
<select id="name" name="name"onkeydown="clearSelect(this,event);"onkeypress="writeSelect(this,event);" style="width:70px;"><option value=""></option><option value="test1">test1</option><option value="test2">test2</option><option value="test3">test3</option></select><script>function clearSelect(obj,e){opt = obj.options[0];opt.selected = "selected";if((e.keyCode== 8) ||(e.charCode==8))//Use the backspace key to edit verbatim deletion{opt.value = opt.value.substring(0, opt.value.length>0?opt.value.length-1:0);opt.text = opt.value;}if((e.keyCode== 46) ||(e.charCode==46))//Use the Delete key to edit verbatim Delete{opt.value = "";opt.text = opt.value;}//Other key responses can also be implemented}function writeSelect(obj,e){opt = obj.options[0];opt.selected = "selected";opt.value += String.fromCharCode(e.charCode||e.keyCode);opt.text = opt.value;}function forbidBackSpace()//In order to avoid backspace's return to the previous page in IE and the edit function of this drop-down box, we need to disable backspace's function. ForbidBackSpace can be written in <Body onkeydown = "forbidBackSpace ();"> In the.{if((event.keyCode == 8) && (event.srcElement.type != "text" && event.srcElement.type != "textarea" && event.srcElement.type != "password")){event.keyCode = 0;event.returnValue = false;}}</script>