diff --git b/Ejercicio_001.html a/Ejercicio_001.html
new file mode 100644
index 0000000..f764f42
--- /dev/null
+++ a/Ejercicio_001.html
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+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>EJERCICIO_001</title>
+    <style>
+        #emailpara{
+            display: none;
+        }
+    </style>
+</head>
+<body>
+    <form action="">
+        <fieldset>
+
+            <legend>Email subscriptions </legend>
+
+            <p id="Ross">
+                <label>
+                    <input onclick="toggleEmail()" type="checkbox" name="subscribe" id="subscripe">
+                    Yes! I would like to receive all of your free candy!
+                    </input>
+                </label>
+            </p>
+            <p id="emailpara">
+                <label>
+                    Email Address:                
+                    <input type="text" name="email" id="email">
+                </label>
+            </p>
+        </fieldset>
+    </form>
+    <script>
+        function toggleEmail() {
+            document.getElementsById("emailpara").style.display="visible";
+        }
+    </script>
+</body>
+</html>
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diff --git b/Ejercicio_002.html a/Ejercicio_002.html
new file mode 100644
index 0000000..8a0b246
--- /dev/null
+++ a/Ejercicio_002.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>EJERCICIO_002</title>
+</head>
+<body>
+    <fieldset>
+        <legend>Billing Information</legend>
+        <p>
+            <label>
+                Postal Address:<br>
+                <input onclick=setHomeAddress() name="postaladdress" id="postaladdress"></input>
+            </label>
+        </p>
+        <p>
+            Home Address:<br>
+            <label>
+                <input " type="checkbox" name="homepostalcheck" id="homepostalcheck">
+                Same as above
+            </label>
+            <br>
+            <input name="homeaddress" id="homeaddress"></input>
+        </p>
+    </fieldset>
+    <script>
+        function setHomeAddress(){
+            document.querySelector('#postaladdress').addEventListener('change', (e)=>{
+                alert(e.target.value);
+            });
+            document.querySelector('#homeaddressdiv').addEventListener('click', ()=>{
+                if(document.querySelector('#homepostalcheck').checked){
+                    document.querySelector('#homeaddress').disabled = true;
+                    document.querySelector('#homeaddress').value = document.querySelector('#postaladdress').value;
+                }else{
+                    document.querySelector('#homeaddress').disabled = false;
+                    document.querySelector('#homeaddress').value = "";
+                }
+            });
+        }
+        
+    </script>    
+</body>
+</html>
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diff --git b/Ejercicio_003.html a/Ejercicio_003.html
new file mode 100644
index 0000000..a7423c3
--- /dev/null
+++ a/Ejercicio_003.html
@@ -0,0 +1,54 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>EJERCICIO_003</title>
+    <link href="css/error.css" rel="stylesheet"/>
+    <script src="js/check.js"></script>
+</head>
+<body>
+    <form action="mailto:me@fakeemail.com" onsubmit="return checkForm();">
+        <fieldset>
+            <legend>Personal details</legend>
+            <p>
+                <label>
+                    Full name:
+                    <input type="text" name="fullname" id="fullname">
+                    </label>
+                    </p>
+                    <p class="errormsg" id="nameerrormsg" style="color: red;">Please enter your name above</p>
+                    <p>
+                    <label>
+                    Street Address:
+                    <input type="text" name="streetaddr" id="streetaddr">
+                </label>
+            </p>
+            <p class="errormsg" id="addrerrormsg" style="color: red;">
+                Please enter your streetaddress
+            </p>
+        </fieldset>
+        <input type="submit" value="Submit it!">
+    </form>
+    <script>
+        function checkForm(){
+            if(document.getElementById("fullname").value ==""){
+                alert("nameerrormsg");
+                document.getElementById("fullname").focus();
+                if(document.getElementById("streetaddr").value ==""){
+                    alert("addrerrormsg");
+                    document.getElementById("streetaddr").focus();
+                }
+                return false;
+            }
+    
+            if(document.getElementById("streetaddr").value ==""){
+                alert("addrerrormsg");
+                document.getElementById("streetaddr").focus();
+                return false;
+            }        
+        }
+        </script>
+</body>
+</html>
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diff --git b/sql/triger.sql a/sql/triger.sql
new file mode 100644
index 0000000..5135b24
--- /dev/null
+++ a/sql/triger.sql
@@ -0,0 +1,18 @@
+
+
+CREATE TABLE REGISTRO_INVENTORY(
+	REGISTRO_ID INTEGER PRIMERY KEY,
+	FECHA DATE,
+	FILM_ID INTEGER NOT NULL,
+	STORE_ID INTEGER NOT NULL,
+	CONSTRAINT FK_FILM_ID FOREIGN KEY(FILM_ID) REFERENCES FILM(FILM_ID), 
+	CONSTRAINT FK_STORE_ID FOREIGN KEY(STORE_ID) REFERENCES STORE(STORE_ID) 
+);
+
+CREATE OR REPLACE TRIGGER INSERTAR_INVENTORY 
+	AFTER UPDATE ON INVENTORY
+	FOR EACH ROW
+	BEGIN
+		 INSERT INTO  REGISTRO_INVENTORY (REGISTRO_ID, FECHA, FILM_ID, STORE_ID) VALUES (DEFAULT, OLD.LAST_UPDATE, OLD.FILM_ID, old.STORE_ID);
+END INSERTAR_INVENTORY;
+/
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