vignere in 25 lines of js

gistfile1.txt

function encrypt(mess, key){
    var i = (mess.length)/(key.length);
    while (i>0){
        key +=key;
        i--;
    }   
    key = key.substring(0, mess.length);

    console.log('message is',mess)
    console.log('key is',key.length);

    var result = ''
    for (var i=0; i < key.length; i++){
        var column = key.charCodeAt(i);
        var row = mess.charCodeAt(i)-97; //subtract 97 to just get the difference from a
        var sum=row+column;
        if (sum > 122){
            sum=((row+column - 123) + 97);
            console.log('too big');
        }   
        result += String.fromCharCode(sum)
    }   
    console.log(result);
}