javascript to show and hide element

for html you need to define ID name of an element

<input type="button" name="clickme1" id="clickme1" value="Click me !!" onclick="JavaScript:showbutton('clickme2')"><BR>
<input type="button" name="clickme2" id="clickme2" value="Click me !!" onclick="JavaScript:showbutton('clickme1')" style="visibility:hidden">

For javascript need this code

function showbutton(idName){
 Element = document.getElementById('clickme2');
 Element.disabled=true;
 Element.style.visibility = "hidden";
 Element = document.getElementById('clickme1');
 Element.disabled=true;
 Element.style.visibility = "hidden";
 clickme1Element = document.getElementById(idName);
 clickme1Element.disabled=false;
 clickme1Element.style.visibility = "visible";
}