html可输入下拉框

<div style="height: 19px">
<span style="position: absolute; border: 1pt solid #c1c1c1; overflow: hidden; width: 148px;
height: 19px; clip: rect(-1px 150px 150px 130px);">
<select name="aabb" id="selCompany" style="width: 150px; height: 20px; margin: -2px;" onchange="javascript:document.getElementById('txtCompany').value=document.getElementById('selCompany').options[document.getElementById('selCompany').selectedIndex].value;">
<option value="---请选择---" style="color: #c2c2c2;">---请选择---</option>
</select>
</span><span style="position: absolute; border-top: 1pt solid #c1c1c1; border-left: 1pt solid #c1c1c1;
border-bottom: 1pt solid #c1c1c1; width: 130px; height: 19px;">
<input type="text" name="ccdd" id="txtCompany" value="---请选择---" style="width: 130px;
height: 15px; border: 0pt;" />
</span>
</div>