Uncaught TypeError: Cannot set property 'value' of null

Question

I\'m trying to pass the entered text to the controller using an ajax request. But i\'m getting athe error \"Uncaught TypeError: Cannot set property \'value\' of null \" whe

Answer 1

You don't have an element with the id u.That's why the error occurs. Note that the global variable document.getElementById("u").value means you are trying to get the value of input element with name u and its not defined in your code.

Answer 2

The problem may where the code is being executed. If you are in the head of a document executing JavaScript, even when you have an element with id="u" in your web page, the code gets executed before the DOM is finished loading, and so none of the HTML really exists yet... You can fix this by moving your code to the end of the page just above the closing html tag. This is one good reason to use jQuery.