How to get selected value from dropdownlist in asp.net using Javascript?

Question

I am populating country dropdownlist from a database. I need to select a value from dropdown list and assign it to textbox by using Javascript.

Code:

var textboxId = document.getElementById("txtCountry");
var dropdownListId =document.getElementById("ddlLocation"); 

var e = document.getElementById("ddlLocation"); 
var strUser = e.options[e.selectedIndex].value;

document.getElementById(textboxId).value = strUser;    
document.getElementById(textboxId).focus(); 

by doing this I am getting error. Any solutions?

Answer 1

Your code is wrong, Look at where I've made the changes to the same code:

var textboxId = document.getElementById("txtCountry");
var e = document.getElementById("ddlLocation"); 
var strUser = e.options[e.selectedIndex].value;
textboxId.value = strUser;    
textboxId.focus(); 

What you did, is you selected your textbox and JS returned you a DOM element of that text box and you wanted to populate it by passing the DOM of the textBox inside the getElementById() function.

Here is where it broke:

document.getElementById(textboxId).value = strUser;

To use getElementById() method, you pass a string value of the id of an element.

Hope this helps.