How does formatBlock work in document.execCommand?

Question

JavaScript

How does document.execCommand(formatBlock, false, 'h1') work? Why does it wrap the entire section of text in this tag, and not the selected one? How can I make the tag wrap only the selected text?

Answer 1

<form name="compForm" onsubmit="if(validateMode()){this.myDoc.value=oDoc.innerHTML;return true;}return false;">