Código Javascript
:
Ver originalfunction insertAtCaret(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;
}
Con esta función lo puedes hacer, sólo debes pasar el id del textarea y el texto a introducir