i want to annimate 3 divs when the user scroll down the page, i followed many ttorials, it didn't work any suggestions how to do it, because the divs haz a defined css classes this is the divs . i wante them to fade up or down or any cool anniation how to acomplish this . please .

  <section  >

        <div class=container>

            <h1>   PRODUITS </h1>

                <div class=row>



                  <a href=pehdeauFrame.php>

                    <div id=mudivsho class=col-md-4 col-sm-4>

                          <div class=panel panel-default>

                            <div  class=panel-body>

                             <h4 style=text-align:center; class=adjst>Tubes PEHD pour Eaux </h4>

                           <img id=imgeaudiv src=assets/images/diveau.jpg>

                          </div>

                          </div>    

                    </div>



                 </a>



                   <a href=pehdTelecomFrame.php>

                   <div id=mudivsho class=col-md-4 col-sm-4>

                          <div class=panel panel-default>

                        <div  class=panel-body>

                             <h4 style=text-align:center; class=adjst>PEHD pour gaine Fibre Optique</h4>

                           <img id=imgeaudiv src=assets/images/divtelecom.jpg>

                        </div>

                    </div>     

                    </div>

                   </a>



                    <a href=http://www.mansouriplast.com/>

                   <div id=mudivsho class=col-md-4 col-sm-4>

                          <div class=panel panel-default>

                        <div  class=panel-body>

                             <h4 style=text-align:center; class=adjst>Tubes PVC</h4>

                            <img id=imgeaudiv src=assets/images/divpvc.jpg>

                        </div>

                    </div>       

                    </div>

                  </a>



                </div>



        </div>

    </section>