diff --git a/source/_static/code/restriction.py b/source/_static/code/restriction.py
index f946de63bae8c2022c0f5444ed9635ec675a5553..cadc274e3b969b1ef8fbe148769c8d2312004660 100644
--- a/source/_static/code/restriction.py
+++ b/source/_static/code/restriction.py
@@ -46,12 +46,15 @@ def one_enz_all_binding_sites2(dna, enzyme):
     pos = dna.find(enzyme[2])
     while pos != -1:
         if positions:
-            positions.append(pos)
-        else:
-            positions = pos + positions[-1]
-        new_seq = dna[pos + 1:]
+            # I have to compute the reeal position
+            # I add the actual position + the previous one + 1 because the new sequence start a 0
+            pos = pos + positions[-1] + 1
+        positions.append(pos)
+        # I start to search from the actual position to the end
+        # i'm searching from the next base
+        pos = pos + 1
+        new_seq = dna[pos:]
         pos = new_seq.find(enzyme[2])
-        pos = pos
     return positions
 
 
@@ -75,3 +78,18 @@ def binding_sites(dna, enzymes):
     positions.sort(key=itemgetter(1))
     return positions 
 
+dna_1 = """tcgcgcaacgtcgcctacatctcaagattcagcgccgagatccccgggggtt
+gagcgatccccgtcagttggcgtgaattcagcagcagcgcaccccgggcgtagaattccagtt
+gcagataatagctgatttagttaacttggatcacagaagcttccagaccaccgtatggatccc
+aacgcactgttacggatccaattcgtacgtttggggtgatttgattcccgctgcctgccagg""".replace('\n', '')
+
+ecor1 = ("EcoRI", "Ecoli restriction enzime I", "gaattc", 1, "sticky")
+ecor5 = ("EcoRV", "Ecoli restriction enzime V", "gatatc", 3, "blunt")
+bamh1 = ("BamHI", "type II restriction endonuclease from Bacillus amyloliquefaciens", "ggatcc", 1, "sticky")
+hind3 = ("HindIII", "type II site-specific nuclease from Haemophilus influenzae", "aagctt", 1, "sticky")
+taq1 = ("TaqI", "Thermus aquaticus", "tcga", 1, "sticky")
+not1 = ("NotI", "Nocardia otitidis", "gcggccgc", 2, "sticky")
+sau3a1 = ("Sau3aI", "Staphylococcus aureus", "gatc", 0, "sticky")
+hae3 = ("HaeIII", "Haemophilus aegyptius", "ggcc", 2, "blunt")
+sma1 = ("SmaI", "Serratia marcescens", "cccggg", 3, "blunt")
+