Click the button to set the show and hide div div

<input type = "button" value = " Settings div Hide" ID = "btn18" /> 
        <input type = "button" value = " Settings div displays" ID = "btn19" /> 
        <div ID = "DV" style = "width: 200px; height: 200px; background-Color: Pink"> </ div> 
        <Script of the type = "text / JavaScript"> // Any css property is in the wording of a word, when operating in jsDOM , the - removed, // back to capitalize the first letter of words such as:. background-color write the backgroundColor function My $ (ID) {
                 return document.getElementById (ID); 
            } 
            My $ ( . "btn18") the onclick = function () { 
                My $ ( "DV"). =. style.display "none";
            };
            my$("btn19").onclick=
            
            
            function(){
                my$("dv").style.display="block";
            };
        </script>