Get value from attribute with javascript

Saturday 14 September 2019

Answer

I have the following code:

echo "
";

In this case, val has the value 8.

I want to access this value with javascript. I have tried the followin method, but it keeps saying that txt is null.

Anyone who can help me?

EDIT:
I solved the problem by placing the code inside window.onload:

    window.onload = function() {
    var txt = document.getElementById("hp");
    var f = txt.getAttribute('val');
    alert(f);
};