diff --git a/aprsd/web/chat/static/js/send-message.js b/aprsd/web/chat/static/js/send-message.js
index 73242e4..8cd3ac0 100644
--- a/aprsd/web/chat/static/js/send-message.js
+++ b/aprsd/web/chat/static/js/send-message.js
@@ -172,7 +172,7 @@ function create_callsign_tab(callsign, active=false) {
   }
 
   item_html = '<li class="nav-item" role="presentation">';
-  item_html += '<button class="nav-link '+active_str+'" id="'+tab_id+'" data-bs-toggle="tab" data-bs-target="#'+tab_content+'" type="button" role="tab" aria-controls="'+callsign+'" aria-selected="true">';
+  item_html += '<button callsign="'+callsign+'" class="nav-link '+active_str+'" id="'+tab_id+'" data-bs-toggle="tab" data-bs-target="#'+tab_content+'" type="button" role="tab" aria-controls="'+callsign+'" aria-selected="true">';
   item_html += callsign+'&nbsp;&nbsp;';
   item_html += '<span onclick="delete_tab(\''+callsign+'\');">×</span>';
   item_html += '</button></li>'
diff --git a/aprsd/web/chat/templates/index.html b/aprsd/web/chat/templates/index.html
index b56f647..3f92c2f 100644
--- a/aprsd/web/chat/templates/index.html
+++ b/aprsd/web/chat/templates/index.html
@@ -49,6 +49,15 @@
                     localStorage.clear();
                 });
             });
+
+            // When a tab is clicked, populate the to_call form field.
+            $(document).on('shown.bs.tab', 'button[data-bs-toggle="tab"]', function (e) {
+                var tab = $(e.target);
+                var callsign = tab.attr("callsign");
+                var to_call = $('#to_call');
+                console.log("Tab clicked on " + callsign);
+                to_call.val(callsign);
+            });
         </script>
     </head>