//FÓRUM
function detect() {
	if (navigator.appName == 'Microsoft Internet Explorer' && navigator.platform == 'MacPPC') {
		return true;
	} else {
		return false;
	}
}


function insert_tarea (txtId, oTag, cTag, defText){
	var txt = document.getElementById(txtId);
	txt.focus();

	if (txt.selectionStart != undefined){
		// -- Firefox, Opera, Safari
		var sel_start = txt.selectionStart;
		var sel_end   = txt.selectionEnd;
	
		if (!cTag){
			txt.value = txt.value.substr(0, sel_start) + oTag + txt.value.substr(sel_end);
			txt.selectionStart = sel_start + oTag.length;
			txt.selectionEnd   = sel_start + oTag.length;
		}else{
			var selText = txt.value.substr(sel_start, sel_end - sel_start);
			if (!selText && defText) selText = defText;
			
			txt.value = txt.value.substr(0, sel_start) + oTag + selText + cTag + txt.value.substr(sel_end);
			txt.selectionStart = sel_start + oTag.length;
			txt.selectionEnd   = sel_start + oTag.length + selText.length;
		}
	}else if (document.selection){
		// -- IE
		var sel = document.selection.createRange();
	
		if (sel) {
			if (!cTag) sel.text = oTag;
			else{
				var selText = sel.text;
				if (!selText && defText) selText = defText;
				var selLength = selText.replace(/\r\n/g, "\n").length;
				
				sel.text = oTag + selText + cTag;
				sel.moveStart ("character", -cTag.length - selLength);
				sel.moveEnd   ("character", -cTag.length);
			}
			sel.select();
		}
	}
}