How To Display The Corresponding Values In The Text Box Depending On Drop Down List On Selecting Radio Button In Javascript?

I am creating a form which ask to select degree using radio buttons. Depending on radio button selected, values in the drop down list changes. Now I want to display some value in t

Solution 1:

document.getElementById ("textboxId").value = "value";

WORKING DEMO

Solution 2:

You should consider putting your Options in an object instead of using a chain of if statements, not only is it easier to look at, but it's also easier to extend later on and you are caching the values.

(function() {
    var options = {
        UG: [
        newOption('Select One', '0'),
        newOption('B.Tech', '1'),
        newOption('B.E', '2')],

        PG: [
        newOption('Select One', '0'),
        newOption('M.Tech', '3'),
        newOption('M.C.A', '4')],

        fallback: [
        newOption('Select Degree First', '00')]
    }

    varSetBranchBydegree = function(degree) {
        var dropdown = document.getElementById("degreepg");
        if (options[degree] !== undefined) {
            dropdown.options = options[degree];
        } else {
            dropdown.options = options.fallback;
        }
    }

    var init = function() {//Setup listeners
    $("#gereepg").change(function(event) {
        var textBox = $("#textbox"), //The textbox with id textbox
            index   = event.target.index;//selected indexif (index == 1 || index == 2) {
            textbox.val("8");
        }
        elseif (index == 3) {
            textbox.val("4");
        }
        elseif (index == 4) {
            textbox.val("6");
        }
    });
}

$(document).ready(init);//run the init method when the site has loaded.
})();

For changing the value of the textbox you need to listen to the onChange event of the select. This can be done by simply adding an attribute onChange="javascriptMethod(this)", but this is generally not recommended because it promotes global scope pollution. Above is an example of doing it with jQuery;