added callook preference setting and lookup code. if checked,

US callsigns will always be queried from callook since it usually
has more data than free qrz.

package.nw/GridTracker.html

@@ -1380,8 +1380,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
               <tr align="center" id="lookupCredentials" style="display: none">
                 <td>
                   Username<input id="lookupLogin" type="text" class="inputTextValue" size="8"
-                  oninput="lookupValueChanged();" / > Password<input id="lookupPassword" type="password"
-                  class="inputTextValue" size="8" oninput="lookupValueChanged();" / >
+                  oninput="lookupValueChanged();" /> Password<input id="lookupPassword" type="password"
+                  class="inputTextValue" size="8" oninput="lookupValueChanged();" />
                 </td>
                 <td>
                   <div class="button" onclick="GetSessionID(lookupQrzTestResult);">Test</div>
@@ -1440,6 +1440,18 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
               </tr>
             </table>
           </div>
+          <div class="mapItem" id="lookupCallookPreferredDiv">
+            <table align="center">
+              <tr>
+                <td align="center">Use Callook before using other service</td>
+              </tr>
+              <tr align="center">
+                <td title="Use Callook before using other service. Free Callook yields more data than free QRZ.">
+                  <input type="checkbox" id="lookupCallookPreferred" onclick="lookupValueChanged()" />
+                </td>
+              </tr>
+            </table>
+          </div>
           <br />
 
           <div id="callsignDatabaseDiv" class="mapItem">

package.nw/lib/gt.js

@@ -14088,6 +14088,7 @@ function lookupValueChanged(what)
     }
   }
   g_appSettings.lookupService = lookupService.value;
+  g_appSettings.lookupCallookPreferred = lookupCallookPreferred.value;
   lookupQrzTestResult.innerHTML = "";
   g_qrzLookupSessionId = null;
   if (lookupService.value == "CALLOOK")
@@ -14150,6 +14151,29 @@ function continueWithLookup(callsign, gridPass)
     "lookupInfoDiv",
     "Looking up <font color='cyan'>" + callsign + "</font>, please wait..."
   );
+
+  if (g_appSettings.lookupCallookPreferred) {
+    var dxcc = callsignToDxcc(callsign);
+    var where;
+    var ccode = 0;
+    if (dxcc in g_dxccToAltName)
+    {
+      where = g_dxccToAltName[dxcc];
+      ccode = g_worldGeoData[g_dxccToGeoData[dxcc]].ccode;
+    }
+    else where = "Unknown";
+    if (ccode == 840)
+    {
+      getBuffer(
+        "https://callook.info/" + callsign + "/json",
+        callookResults,
+        gridPass,
+        "https",
+        443,
+        true
+      );
+    }
+  }
   if (g_appSettings.lookupService != "CALLOOK")
   {
     g_qrzLookupCallsign = callsign;