diff --git a/kfet/templates/kfet/kpsul.html b/kfet/templates/kfet/kpsul.html
index b76a3fc1..2a6eec56 100644
--- a/kfet/templates/kfet/kpsul.html
+++ b/kfet/templates/kfet/kpsul.html
@@ -310,9 +310,11 @@ $(document).ready(function() {
     // -----
 
     function requestAuth(data, callback) {
+        var content = getErrorsHtml(data);
+        content += '<input type="password" name="password" autofocus>',
         $.confirm({
             title: 'Authentification requise',
-            content: '<input type="password" name="password" autofocus>',
+            content: content,
             backgroundDismiss: true,
             animation:'top',
             closeAnimation:'bottom',
@@ -332,6 +334,44 @@ $(document).ready(function() {
         });
     }
 
+    // -----
+    // Errors ajax
+    // -----
+
+    function getErrorsHtml(data) {
+        var content = '';
+        if ('operation_group' in data['errors']) {
+            content += 'Général';
+            content += '<ul>';
+            if (data['errors']['operation_group'].indexOf('on_acc') != -1)
+                content += '<li>Pas de compte sélectionné</li>';
+            if (data['errors']['operation_group'].indexOf('checkout') != -1)
+                content += '<li>Pas de caisse sélectionnée</li>';
+            content += '</ul>';
+        }
+        if ('missing_perms' in data['errors']) {
+            content += 'Permissions manquantes';
+            content += '<ul>';
+            for (var i=0; i<data['errors']['missing_perms'].length; i++)
+                content += '<li>'+data['errors']['missing_perms'][i]+'</li>';
+            content += '</ul>';
+        }
+        if ('negative' in data['errors'])
+            content += '<a class="btn btn-primary" href="/k-fet/accounts/'+account_data['trigramme']+'/edit" target="_blank">Autorisation de négatif requise</a>';
+        return content;
+    }
+
+    function displayErrors(html) {
+        $.alert({
+            title: 'Erreurs',
+            content: html,
+            backgroundDismiss: true,
+            animation: 'top',
+            closeAnimation: 'bottom',
+            keyboardEnabled: true,
+        });
+    }
+
     // -----
     // Perform operations
     // -----
@@ -362,6 +402,9 @@ $(document).ready(function() {
                 case 403:
                     requestAuth(data, performOperations);
                     break;
+                case 400:
+                    displayErrors(getErrorsHtml(data));
+                    break;
             }
         });
     }
@@ -828,7 +871,7 @@ $(document).ready(function() {
 
         operation_html
             .find('#id_form-__prefix__-type').val(type).end()
-            .find('#id_form-__prefix__-amount').val(amount).end()
+            .find('#id_form-__prefix__-amount').val((parseFloat(amount)).toFixed(2)).end()
             .find('#id_form-__prefix__-article').val(article).end()
             .find('#id_form-__prefix__-article_nb').val(article_nb).end()
             .find('#id_form-__prefix__-is_checkout').val(is_checkout);