Web Teacher Software
web database
CGI tutorial
database consulting
web database training
contact us about web 
database software
Hosted Database Solutions
webteacher home
Web Teacher Consulting

javascript tutorial graphic

Webteacher Software now offers

onChange Events

Certain types of form objects, such as checkboxes and menus can't have a text cursor, so they can't trigger an onBlur event when you make changes. You can use the onChange event to trigger your functions when the user has make his/her selec tion on these items.

function getSelect(s) {
  return s.options[s.selectedIndex].value

<SELECT NAME="list" SIZE=1 OnChange="location=getSelect(this)">
<OPTION value="#"> Choose a search engine
<OPTION value="http://www.yahoo.com"> Yahoo
<OPTION value="http://www.lycos.com"> Lycos
<OPTION value="http://www.excite.com"> Excite

Since Netscape forgot to provide a function for getting the value of a select box, I wrote one which I place in the <SCRIPT> tags of any page that has a selection list. Simply copy the getSelect(s) function into your <SCRIPT> area, and getSelect(form.mylist) will return the Value of the current mylist selection.

In this example we used the word this as a shortcut. We could have said getSelect(form.list), however since the command was inside the <SELECT> tag, the word this automatically referred to the current <SELECT> object. In this example, if Lycos was selected, then the event onChange="location=getSelect(this)" would be interpreted as location="http://www.lycos.com".

Check Boxes

Since a checkbox is selected/deselected with a mouse click, the onClick event will trigger your function whenever the checkbox is changed. Each checkbox has a property called checked which is equal to true or false depending on whether the box is currently checked. This example runs a function when the box is clicked, and displays a message if the box is checked.

function rushbox(checked) {
if (checked==true) {alert(" LIFT OFF! ")}
<INPUT TYPE=checkbox NAME="rush" OnClick="rushbox(form.rush.checked)"
Rush this order <FORM>
Rush this order

Page Load events

Home | WebData - Web Database Software | Javascript | CGI | Consulting | Map Builder | Contact Us | The Press Room