UI will now disable Nametable or Bank export if the other surface is selected.

app/js/ctrls/CTRLIO.js

 import JSONSchema from "/app/js/common/JSONSchema.js";
 import NESBank from "/app/js/models/NESBank.js";
 import NESPalette from "/app/js/models/NESPalette.js";
+import NESNameTable from "/app/js/models/NESNameTable.js";
 import CTRLPalettesStore from "/app/js/ctrls/CTRLPalettesStore.js";
 import CTRLBanksStore from "/app/js/ctrls/CTRLBanksStore.js";
 import CTRLNameTablesStore from "/app/js/ctrls/CTRLNameTablesStore.js";
 }
 
 function HANDLE_SurfChange(surf){
+  var enableclass = "";
   if (surf instanceof NESBank){
     SURF = surf;
+    enableclass = "surf-bank";
   } else {
     SURF = null;
+    if (surf instanceof NESNameTable)
+      enableclass="surf-nametable";
+  }
+
+  var e = document.querySelectorAll(".surf-export");
+  for (let i=0; i < e.length; i++){
+    var ea = e[i].querySelector("a");
+    if (ea){
+      if (e[i].classList.contains(enableclass)){
+        e[i].classList.remove("disable-links");
+        ea.classList.remove("pure-menu-disabled");
+      } else {
+        e[i].classList.add("disable-links");
+        ea.classList.add("pure-menu-disabled");
+      }
+    }
   }
 }
 

sass/core.scss

   display: flex;
 }
 
+.disable-links {
+  pointer-events: none;
+}
+
 canvas.canvas-item-selected{
   border: 3px solid #FF0000;
 }

views/header_menu.html

     <li class="pure-menu-item pure-menu-has-children pure-menu-allow-hover">
       <a href="#" id="exportchr" class="pure-menu-link">Export</a>
       <ul class="pure-menu-children">
-        <li class="pure-menu-item" emit="modal-open" emit-args='{"cls":".export-chr"}'>
-          <a href="#" class="pure-menu-link">Bank to CHR</a>
-        </li>
         <li class="pure-menu-item" emit="export-pal-asm">
           <a href="#" class="pure-menu-link">Palette to ASM</a>
         </li>
-        <li class="pure-menu-item" emit="modal-open" emit-args='{"cls":".export-nametable"}'>
+        <li class="surf-export surf-bank pure-menu-item" emit="modal-open" emit-args='{"cls":".export-chr"}'>
+          <a href="#" class="pure-menu-link">Bank to CHR</a>
+        </li> 
+        <li class="surf-export surf-nametable pure-menu-item" emit="modal-open" emit-args='{"cls":".export-nametable"}'>
           <a href="#" class="pure-menu-link">Nametable to ASM</a>
         </li>
       </ul>