java script to validate combobox

[bobby421]

have to validate my web page using java script. I have one dropdown list also . I need a javascript to validate weather any item in dropdownlist is selected or not. e.g ddlDrop is my dropdownlist.

To validate other controls I am using following
function validate()
{
if (document.getElementById("<%=txtUserName.ClientID% >").value=="")
{
alert("Please Pprovide UserName");
document.getElementById("<%=txtUserName.ClientID%> ").focus();
return false;
}
if (document.getElementById("<%=txtPassword.ClientID% >").value=="")
{
alert("Please provide Password");
document.getElementById("<%=txtPassword.ClientID%> ").focus();
return false;
}

[acoder]

I assume the user is not allowed to select the first item in the list.

You can use the selectedIndex property. Check if it's 0. If it is, that means the first item is selected.

[pbmods]

You can check the selected index of a select by using:

document.getElementById('theElement').selectedIndex
 

You can check the value of the selected option by using:

var theElement = document.getElementById('theElement');
theElement.options[theElement.selectedIndex].value
 

http://www.w3schools.com/htmldom/dom_obj_select.asp
http://www.w3schools.com/htmldom/dom_obj_option.asp