coding new field

<label>No Matrik Peserta </label>
    <input type="text" name="NoMatrik_Staf" id="NoMatrik_Staf" />
    <input type="button" onclick="addInput()" name="NoMatrik_Staf" id="NoMatrik_Staf" value="+ Pelajar"/><br/>

//coding for add new text field
<span id="responce"></span>
<script>
var countBox =1;
var boxName = 0;
function addInput()
{
var boxName="textBox"+countBox;
document.getElementById('responce').innerHTML+='<br/><input type="text" id="NoMatrik_Staf" value="" "  /><br/>';
countBox += 1;
}