커서위치에 글자 삽입 스크립트

function insertAtCursor(areaId,text)
{
	var txtarea = document.getElementById(areaId);
	var scrollPos = txtarea.scrollTop;
	var strPos = 0;
	var br = ((txtarea.selectionStart || txtarea.selectionStart == '0') ?
		"ff" : (document.selection ? "ie" : false ) );
	if (br == "ie") {
		txtarea.focus();
		var range = document.selection.createRange();
		range.moveStart ('character', -txtarea.value.length);
		strPos = range.text.length;
	}
	else if (br == "ff") strPos = txtarea.selectionStart;

	var front = (txtarea.value).substring(0,strPos);
	var back = (txtarea.value).substring(strPos,txtarea.value.length);
	txtarea.value=front+text+back;
	strPos = strPos + text.length;
	if (br == "ie") {
		txtarea.focus();
		var range = document.selection.createRange();
		range.moveStart ('character', -txtarea.value.length);
		range.moveStart ('character', strPos);
		range.moveEnd ('character', 0);
		range.select();
	}
	else if (br == "ff") {
		txtarea.selectionStart = strPos;
		txtarea.selectionEnd = strPos;
		txtarea.focus();
	}
	txtarea.scrollTop = scrollPos;
}

[출처] stackoverflow