convert integer to spreadsheet column name, a, b, c, ... aa, etc.

gistfile1.js

function colName(n) {
    var s = "";
    while(n >= 0) {
        s = String.fromCharCode(n % 26 + 97) + s;
        n = Math.floor(n / 26) - 1;
    }
    return s;
}