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Window top Property

❮ Window Object

Example

When the "Check window" button is clicked, the function check() is called and the current window status is checked. If the topmost window (window.top) is different from the current window (window.self), then output that "This window is not the topmost window! Am I in a frame?". If the topmost window equals the current window, then fire the else statement:

function myFunction() {
    if (window.top != window.self) {
        document.getElementById("demo").innerHTML = "This window is NOT the topmost window!";
    } else {
        document.getElementById("demo").innerHTML = "This window is the topmost window!";
    }
}
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Definition and Usage

The top property returns the topmost browser window of the current window.

This property is read-only.


Browser Support

Property
top Yes Yes Yes Yes Yes

Syntax

window.top

Technical Details

Return Value: A reference to the topmost window in the window hierarchy

❮ Window Object