echo '<td id="texttwo_'.$row['id'].'">
<input type="number" min="0" max="999" name="india"
onChange="sum('.$row['id'].');" class="txtbox" disabled="disabled" ></td>';
<script>
var txtSecondNumberValue = document.getElementById('texttwo_'+rowid).value;
alert(txtSecondNumberValue );
it shows
undefined
how to solve this.