diff --git a/htdocs/lib/functions.inc.php b/htdocs/lib/functions.inc.php
index dd39afbda80..e03e1bc4017 100644
--- a/htdocs/lib/functions.inc.php
+++ b/htdocs/lib/functions.inc.php
@@ -328,9 +328,9 @@ function print_liste_field_titre($name, $file, $field, $begin="", $options="")
   global $conf;
 
   print $name." ";
-  print '<a href="'.$file.'?sortfield='.$field.'&sortorder=asc&begin='.$begin.$options.'">';
+  print '<a href="'.$file.'?sortfield='.$field.'&amp;sortorder=asc&begin='.$begin.$options.'">';
   print '<img src="'.DOL_URL_ROOT.'/theme/'.$conf->theme.'/img/1downarrow.png" border="0"></a>';
-  print '<a href="'.$file.'?sortfield='.$field.'&sortorder=desc&begin='.$begin.$options.'">';
+  print '<a href="'.$file.'?sortfield='.$field.'&amp;sortorder=desc&begin='.$begin.$options.'">';
   print '<img src="'.DOL_URL_ROOT.'/theme/'.$conf->theme.'/img/1uparrow.png" border="0"></a>';
 }
 
@@ -351,9 +351,9 @@ function print_liste_field_titre_new($name, $file, $field, $begin="", $options="
   print '<td '. $td.'>';
     }
   print $name."&nbsp;";
-  print '<a href="'.$file.'?sortfield='.$field.'&sortorder=asc&begin='.$begin.$options.'">';
+  print '<a href="'.$file.'?sortfield='.$field.'&amp;sortorder=asc&begin='.$begin.$options.'">';
   print '<img src="'.DOL_URL_ROOT.'/theme/'.$conf->theme.'/img/1downarrow.png" border="0"></a>';
-  print '<a href="'.$file.'?sortfield='.$field.'&sortorder=desc&begin='.$begin.$options.'">';
+  print '<a href="'.$file.'?sortfield='.$field.'&amp;sortorder=desc&begin='.$begin.$options.'">';
   print '<img src="'.DOL_URL_ROOT.'/theme/'.$conf->theme.'/img/1uparrow.png" border="0"></a>';
   print "</td>";
 }
@@ -436,12 +436,12 @@ function print_barre_liste($titre, $page, $file, $options='', $sortfield='', $so
 
   if (strlen($sortfield))
     {
-      $options .= "&sortfield=$sortfield";
+      $options .= "&amp;sortfield=$sortfield";
     }
 
   if (strlen($sortorder))
     {
-      $options .= "&sortorder=$sortorder";
+      $options .= "&amp;sortorder=$sortorder";
     }
 
   // affichage des fleches de navigation