diff --git a/pdb-ui/src/main/resources/resources/js/search.js b/pdb-ui/src/main/resources/resources/js/search.js
index b7f1e8a..ddf3a5e 100644
--- a/pdb-ui/src/main/resources/resources/js/search.js
+++ b/pdb-ui/src/main/resources/resources/js/search.js
@@ -426,6 +426,9 @@ function sendPlotRequest(query){
 		if (e.status == 404){
 			$('#result-image').text("No data points found for query: " + query);
 		}
+		else if (e.status == 503){
+			$('#result-image').text("Too many parallel requests.");
+		}
 		else{
 			$('#result-image').text("FAILED: " + JSON.parse(e.responseText).message);
 		}