why this code shows <b> tags?
<html >
<head>
<title>My Editor</title>
<script type="text/javascript">
var displayText="";
function boldText(){
oForm = document.forms[0];
oTextarea = oForm.elements["txtArea"];
textarea_val = oTextarea.value;
oTextarea.value = textarea_val.bold();
}
</script>
</head>