first-last-name-regex

var re = /^[a-z ,.'-]{2}+$/i; 
var str = '  ';
var m;
 
if ((m = re.exec(str)) !== null) {
    if (m.index === re.lastIndex) {
        re.lastIndex++;
    }
    // View your result using the m-variable.
    // eg m[0] etc.
}