If the function is written to execute the function immediately or put inside other functions, the execution fails.

I am doing a navigation home page, do search, want to use Baidu search intelligent prompt function, encountered a strange problem. The code is as follows:

<body>
    <input type="text" id="q">
    <ul id="show"></ul>
    <script>
        function solve(data) { //API
            var Show = document.getElementById("show");
            var html = "";

            if (data.s.length) {
                Show.style.display = "block";
                var len = data.s.length;
                for (var i = 0; i < len; iPP) { //
                    html += "<li><a target="_blank" href="http://www.baidu.com/s?wd=" + data.s[i] + "">" + data.s[i] + "</a></li>";
                }
                Show.innerHTML = html;
            } else {
                Show.style.display = "none";
            }
        }

        var oQ = document.getElementById("q"),
            Show = document.getElementById("show");

        oQ.onkeyup = function() { //
            if (this.value != "") {
                var oScript = document.createElement("script"); //script
                oScript.src = "http://suggestion.baidu.com/su?wd=" + this.value + "&cb=solve";
                document.body.appendChild(oScript);
            } else {
                Show.style.display = "none";
            }
        }
    </script>
</body>

the current code is executable and can run the correct results. But when I put it inside another function, the execution failed. The
code is as follows:

<body>
    <input type="text" id="q">
    <ul id="show"></ul>
    <script>
        (function() {
            function solve(data) { //API
                var Show = document.getElementById("show");
                var html = "";

                if (data.s.length) {
                    Show.style.display = "block";
                    var len = data.s.length;
                    for (var i = 0; i < len; iPP) { //
                        html += "<li><a target="_blank" href="http://www.baidu.com/s?wd=" + data.s[i] + "">" + data.s[i] + "</a></li>";
                    }
                    Show.innerHTML = html;
                } else {
                    Show.style.display = "none";
                }
            }

            var oQ = document.getElementById("q"),
                Show = document.getElementById("show");

            oQ.onkeyup = function() { //
                if (this.value != "") {
                    var oScript = document.createElement("script"); //script
                    oScript.src = "http://suggestion.baidu.com/su?wd=" + this.value + "&cb=solve";
                    document.body.appendChild(oScript);
                } else {
                    Show.style.display = "none";
                }
            }
        })()
    </script>
</body>

does any god know why?