diff --git a/koha-tmpl/intranet-tmpl/prog/en/js/members.js b/koha-tmpl/intranet-tmpl/prog/en/js/members.js
index bbb1e30e56..766495c817 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/js/members.js
+++ b/koha-tmpl/intranet-tmpl/prog/en/js/members.js
@@ -146,6 +146,7 @@ var statut=0;
 	if (statut==1){
 			//alert if at least 1 error
 				alert(message+"\n"+message_champ);
+				return false;
 	}
 	else 
 	{
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tmpl b/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tmpl
index 6bfdeb2422..31e7a9291c 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tmpl
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/members/memberentrygen.tmpl
@@ -584,9 +584,9 @@ patron <!-- TMPL_VAR NAME="surname" --> <!-- TMPL_VAR name="firstname" -->
 <!-- /TMPL_IF -->
     <div id="action">
       <!-- TMPL_IF NAME="opadd" -->
-        <input type="button" name="step4" onclick="check_form_borrowers();unique();" value="Add member" />
+        <input type="button" name="step4" onclick="return check_form_borrowers();unique();" value="Add member" />
       <!-- TMPL_ELSE -->
-        <input type="button" name="step4" onclick="check_form_borrowers();" value="Modify member" />
+        <input type="button" name="step4" onclick="return check_form_borrowers();" value="Modify member" />
       <!--/TMPL_IF -->
     </div>
 </form>