webView content height

Hi in a window in IOS i have a button, a label and bellow a webView with content. I can see all good but the problem is in the webView height, the height it's not only the content it's more. How can i limit the height of the webView or the html document to the content?

I trie with something like this but not works

webview.addEventListener('load',function(e){
        actualHeight    = e.source.evalJS("document.height;");
        e.source.height = actualHeight;
});