Adding a value to a dropdown through Javascript in c#

Question

Hi,

 

I want to add a value to the Dropdownlist through Javascript but am getting Runtime Errors.

 

Below is my code, can some one help me on this. I tried multiple approches from webSearch but are not working.

 

function run() {

debugger;

var ddlvalue = document.getElementById("<%=ddlTest.ClientID%>");

if (ddlvalue.options[ddlvalue.selectedIndex].value == "0")

{

alert("Please select a value from the Dropdown!");

return;

}

var option = document.createElement('option');

option.text = 'UK';

option.value = '5';

ddlvalue.add(option); //Tried no error but value not getting added to Dropdown list.

document.getElementById("<%=ddlTest.ClientID%>").add(option);//Tried giving runtime error.