JSP using JavaScript dynamic insert delete input box implementation code

JavaScript code:

 
<script language="javascript"> 
function addrows(){ 
var len = optionlist.rows.length; //I get the number of rows in the table
var obj = optionlist.insertRow(len);//Insert on the last line
 
obj.insertCell(0); 
obj.cells(0).innerHTML=" options " + (len+1) + " : <input type=text name=option size=28>"; 
} 
function deleterow(){ 
var len = optionlist.rows.length; 
if(len <= 1) { 
alert(" At least one option "); 
} 
else { 
optionlist.deleteRow(len-1);//Delete the last term
} 
} 
function getOptionCount(){ 
return optionlist.rows.length; 
} 
</script> 

Key code in a Jsp page

 
<input type="button" id="bt1" value=" Add a option " onClick="addrows();"> 
<input type="button" id="bt2" value=" Delete options " onClick="deleterow();"> 

Set the id of the table so that JavaScript can recognize the table

 
<table id="optionlist"> 
</table>