You can't do it.
YOu will need to learn to use DOM methods, instead.
Not only that... You never even *call* your numbercheck function.
Not only that... If you use a submit button, then the page *will* be submitted and the screen will be wiped out and the page reloaded from the browser.
In short...keep trying. You have a ways to go. But not a mile, maybe a meter or two.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.