Click in OK button inside an Alert (Selenium IDE)

Try Selenium 2.0b1. It has different core than the first version. It should support popup dialogs according to documentation:

Popup Dialogs

Starting with Selenium 2.0 beta 1, there is built in support for handling popup dialog boxes. After you’ve triggered and action that would open a popup, you can access the alert with the following:

Java

Alert alert = driver.switchTo().alert();

Ruby

driver.switch_to.alert

This will return the currently open alert object. With this object you can now accept, dismiss, read it’s contents or even type into a prompt. This interface works equally well on alerts, confirms, prompts. Refer to the JavaDocs for more information.

The question isn't clear - is this for an alert on page load? You shouldn't see any alert dialogues when using Selenium, as it replaces alert() with its own version which just captures the message given for verification.

Selenium doesn't support alert() on page load, as it needs to patch the function in the window under test with its own version.

If you can't get rid of onload alerts from the application under test, you should look into using GUI automation to click the popups which are generated, e.g. AutoIT if you're on Windows.

Use the Alert Interface, First switchTo() to alert and then either use accept() to click on OK or use dismiss() to CANCEL it

Alert alert_box = driver.switchTo().alert();
alert_box.accept(); 

or

Alert alert_box = driver.switchTo().alert();
alert_box.dismiss(); 

about Selenium IDE, I am not an expert but you have to add the line "choose ok on next confirmation" before the event which trigger the alert/confirm dialog box as you can see into this screenshot:

For selenium, an alert is the one which raised using javascript e.g.

 javascript:alert();

There is one basic check to verify whether your alert is actually a javascript alert or just a div-based box for displaying some message. If its a javascript alert, you wont be able to see it on screen while running the selenium script.

If you are able to see it, then you need to get the locator of the ok button of the alert and use selenium.click(locator) to dismiss the alert. Can help you better if you can provide more context:

1. IDE or RC?
2. HTML code of the alert
3. your selenium script.

Vamyip

The new Selenium IDE (released in 2019) has a much broader API and new documentation.

I believe this is the command you'll want to try:

webdriver choose ok on visible confirmation

Described at:

https://www.seleniumhq.org/selenium-ide/docs/en/api/commands/#webdriver-choose-ok-on-visible-confirmation

There are other alert-related API calls; just search that page for alert