19 lines
378 B
HTML
19 lines
378 B
HTML
<!DOCTYPE html>
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<html>
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<head>
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<meta charset="utf-8">
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</head>
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<body>
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<script>
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function setHandler() {
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window.onbeforeunload = function() {
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return "There are unsaved changes. Leave now?";
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};
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}
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</script>
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<button onclick="setHandler()">Set window.onbeforeunload</button>
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<a href="http://example.com">Leave for EXAMPLE.COM</a>
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</body>
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</html>
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