Function To Convert String To Ordered List

I have a string with javascript linebreaks with /n. I want to make a function that will make a text only ordered list (text within a text area... i.e. I don't want to us ol and li)

For example,
Spot1
Spot2
Spot3

would be converted to
A) Spot 1 -
B) Spot 2 -
C) Spot 3 -

So far I think I need to use an array, and replace...
Code:
function AddLabels(element_id) {
x=document.getElementById(element_id).value;
countlinebreaksstr=x
try {
return((countlinebreaksstr.match(/[^
]*
[^
]*/gi).length));
} catch(e) {
return 0;
}
var myArray = [A,B,C,D,E,F,G,H];
var i=0;
for (i=0;i<=10;i++)
{
}