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<html><body>A Checkbox: <input type="checkbox" id="myCheck" value="myvalue"><p>Click the buttons below to display and/or change the value of the value attribute of the checkbox above.</p><button onclick="display()">Display name</button><button onclick="change()">Change name</button><script>function display() { var x = document.getElementById("myCheck").value; alert("The value of the checkbox is: " + x);}function change() { var x = document.getElementById("myCheck").value = "newCheckboxValue"; alert ("The value was changed to: " + x);}</script></body></html>