diff --git a/value_builder/unimarc_field_126a.pl b/value_builder/unimarc_field_126a.pl
index 0c4db5ce8e..7d0c23c921 100755
--- a/value_builder/unimarc_field_126a.pl
+++ b/value_builder/unimarc_field_126a.pl
@@ -52,7 +52,7 @@ function Blur$function_name(subfield_managed) {
 
 function Clic$function_name(i) {
 	defaultvalue=document.forms[0].field_value[i].value;
-	newin=window.open(\"../plugin_launcher.pl?plugin_name=unimarc_field_126a.pl&index=\"+i+\"&result=\"+defaultvalue,\"unimarc field 126a\",'width=1000,height=575,toolbar=false,scrollbars=yes');
+	newin=window.open(\"../plugin_launcher.pl?plugin_name=unimarc_field_126a.pl&index=\"+i+\"&result=\"+defaultvalue,\"unimarc field 126a\",'width=800,height=400,toolbar=false,scrollbars=yes');
 
 }
 </script>