Add text to text area using javascript

Question

How can I add custom text to already written text in textarea using javascript??Thanks...

Answer 1

function addText(elId,text) {
    document.getElementById(elId).value += text;
}

or:

function addText(elId,text) {
    var obj = document.getElementById(elId);
    var txt = document.createTextNode(text);
    obj.appendChild(txt);
}