diff --git a/plasmid/source/core-plugins/newbrowser/1/as/webapps/newbrowser/html/js/views/SampleForm.js b/plasmid/source/core-plugins/newbrowser/1/as/webapps/newbrowser/html/js/views/SampleForm.js
index 6c0539bb9b88b9449b89edd05a566be25d67d6f3..8c1607ccc58c1b8f002ba03d303f149f96868411 100644
--- a/plasmid/source/core-plugins/newbrowser/1/as/webapps/newbrowser/html/js/views/SampleForm.js
+++ b/plasmid/source/core-plugins/newbrowser/1/as/webapps/newbrowser/html/js/views/SampleForm.js
@@ -305,7 +305,7 @@ function SampleForm(serverFacade, inspector, containerId, profile, sampleTypeCod
 		var localReference = this;
 		$( "#copyButton" ).click(function() {
 			var component = "<div class='form-horizontal'>"
-				component += "Input a new code for the duplicate, the duplicate will not have parents or children: <br><br>";
+				component += "<span class='glyphicon glyphicon-warning-sign'></span> Input a new code for the duplicate, the duplicate will not have parents or children: <br><br>";
 				component += "<div class='form-group col-md-9'>";
 				component += "<label class='control-label  " + localReference.labelColumnClass+ "'>Code&nbsp;(*):</label>";
 				component += "<div class='" + localReference.controlColumnClass + "'>";
@@ -334,6 +334,8 @@ function SampleForm(serverFacade, inspector, containerId, profile, sampleTypeCod
 					var newSampleCodeForCopyValue = newSampleCodeForCopy.val();
 					localReference.createSample(newSampleCodeForCopyValue);
 					Util.unblockUI();
+				} else {
+					Util.showError("Invalid code.", function() {}, true);
 				}
 			});