Autocomplete Question

I've recently got a hold of a function that allows for predictive / autocomplete text (shown below). This is fine when Im using it on the first word, however what I'm trying to do is to get it on anything after the first word (ie the second or third word in the text box). If anyone could give some pointers I would be much obliged.

function autoComplete (dataArray, input, evt) {

if (temp.length == 0) {
return;
}
var match = false;
for (var i = 0; i < dataArray.length; i++) {
if ((match = dataArray[i].toLowerCase().indexOf
(temp.toLowerCase()) == 0)) {
break;
}
}
if (match) {
var typedText = input.value;
if (typeof input.selectionStart != 'undefined') {
if (evt.keyCode == 16) {
return;
}
input.value = dataArray[i];
input.setSelectionRange(typedText.length, input.value.length);
}
else if (input.createTextRange) {
if (evt.keyCode == 16) {
return;
}
input.value = dataArray[i];
var range = input.createTextRange();
range.moveStart('character', typedText.length);
range.moveEnd('character', input.value.length);
range.select();
}
else {
if (confirm("Are you looking for '" + dataArray[i] + "'?")) {
input.value = dataArray[i];
}
}
}
}