可输入select

1.

				             <input type="text" style="width: 130px;" name="xm" value="">
						        <select name="select" style="position:absolute;width: 148px;margin-left:-130px; clip: rect(0 148 22 130);" id="select" onchange="xm.value=select.options[select.selectedIndex].text;xm.select()">
						          <option value="1" selected>aa</option>
						          <option value="2">dddd</option>
						          <option value="2">bb</option>
						          <option value="2">ddccdd</option>
						        </select> 

2.

<div style="position:relative;">
<span id="aaa" style="margin-left:200px;width:18px;overflow:hidden;">								<select id="bbb" class="text" style="width:218px;margin-left:-200px"  onchange="this.parentNode.nextSibling.value=this.value">
<option value="" ></option>
<option value="aa">bb</option>
<option value="bb">aa</option>
</select>
</span><input name="cc" id="cc"  class="text" style="width:200px;position:absolute;left:0px;" onclick="">
</div>