Recreate chart on subsequent model runs

ipmd/templates/ipmd/saddlegallmidgeform.html

@@ -99,6 +99,9 @@
     var selectList = document.getElementById("weatherStationId");
     
     var weatherData = undefined;
+
+    // Object that will hold the chart. Must be destroyed and recreated if you run the model more than once
+    let resultChart = undefined;
     
     async function initPage() {
         currentModelMetaData = await getModelMetadata("adas.dss","HAPDMA");
@@ -505,7 +508,11 @@
 
         const ctx = document.getElementById('resultChart');
 
-        new Chart(ctx, {
+        if(resultChart !== undefined)
+        {
+            resultChart.destroy();
+        }
+        resultChart = new Chart(ctx, {
             type: "line",
             options: {
                 responsive: true,