I'm new to Javascript but not programming. I'm trying to write a program that exchanges information with a server. I can't get it to work and even simplifying and borrowing other peoples code doesn't help. What I'm doing wrong?
Here is the client:
<!DOCTYPE html>
<html>
<head>
<title>Testing</title>
</head>
<body>
<script>
GET_JSON = function(callback) {
var req = new XMLHttpRequest();
req.open(POST, "http://www.skutan.com/cgi-bin/hvserver.cgi", true);
req.onreadystatechange = function() {
if (this.readyState == 4) {
callback(JSON.parse(req.responseText));
}
}
req.send("a=2&b=1");
}
JSONCallback = function(JSONObj) {
alert(JSONObj);
};
</script>
<button type="button" onclick="GET_JSON(JSONCallback)">Test</button>
<h1>.</h1>
<span id="koord"></span>
</body>
</html>
The server is witten in perl and looks like this:
#!/usr/bin/perl -wT
use strict;
use CGI qw(:standard);
my @fields = param;
my $json_ut = "{\"a\": 1, \"b\": 2}";
print("Content-type: application/json; charset=utf-8\n\n");
print("$json_ut");
Why don't I get any alert in the client?
If you checked your brower's console, you'll see an error such as
with a reference to the line
It should be