Add them all to s
inside the loop, not after the loop
function dotest() {
var inputs = document.getElementsByTagName("input");
if (inputs.length > 0) {
var s = document.URL + "\n";
s += "-- Inputs list start --\n";
for (var i = 0; i < inputs.length; i++) {
var inputdata = inputs[i];
var imputdatas = '';
imputdatas += inputdata.name + ",";
imputdatas += inputdata.id + ",";
imputdatas += inputdata.type + ",";
imputdatas += inputdata.value + "\n";
s += imputdatas;
// ^^^ needs to be here
}
s += "-- End -\n\n";
}
if (s) {
alert(s);
}
}