fix game data buttons/inputs

script.js

@@ -29,12 +29,13 @@ async function run() {
         pageButton.addEventListener('touchend', pagination);
     }
 
-    const gameDataInput = document.getElementById("game-data");
+    const gameDataInput         = document.getElementById("game-data");
+    const buttonGameDataProceed = document.getElementById("game-data-next");
 
     function new_game() {
         load_default_game_data();
         // we don't need to look at the default game data, so skip ahead to the image page
-        document.getElementById("game-data-next").click();
+        buttonGameDataProceed.click();
     }
 
     function clear_game() {
@@ -65,10 +66,22 @@ async function run() {
 
     document.getElementById("game").addEventListener("change", function() {
         readFile(this, function (e) {
-            gameDataInput.innerHTML = e.target.result;
+            gameDataInput.value = e.target.result;
+            checkGameData();
         }, "text");
     });
 
+    function checkGameData() {
+        if (gameDataInput.value.length > 0) {
+            buttonGameDataProceed.removeAttribute("disabled");
+        } else {
+            buttonGameDataProceed.setAttribute("disabled", "disabled");
+        }
+    }
+
+    gameDataInput.addEventListener("change", checkGameData);
+    gameDataInput.addEventListener("keyup",  checkGameData);
+
     const preview = document.getElementById("preview");
     preview.style.display = "none";
 
@@ -89,6 +102,15 @@ async function run() {
     const importButton = document.getElementById("import");
     importButton.addEventListener("click",    addTiles);
     importButton.addEventListener("touchend", addTiles);
+
+    function reset() {
+        gameDataInput.innerHTML = '';
+        preview.removeAttribute("src");
+    }
+
+    let resetButton = document.getElementById("reset");
+
+    resetButton.addEventListener("click", reset);
 }
 
 run();