Please check below link for live demo
http://amitblog-developer-edition.ap1.force.com/CustomPopup
Class Should be:
public with sharing class CustomPopupController {
public boolean showPopup {get;set;}
public CustomPopupController ()
{
showPopup = false;
}
public PageReference openPopup()
{
showPopup = true;
return null;
}
public PageReference Cancel()
{
showPopup = false;
return null;
}
}
<apex:page controller="CustomPopupController">
<style type="text/css">
.popupBackground{
background-color:black;
opacity: 0.20;
filter: alpha(opacity = 20);
position: absolute;
width: 100%;
height: 100%;
top: 0;
left: 0;
z-index: 9998;
}
.custPopup{
background-color: white;
border-width: 2px;
border-style: solid;
z-index: 9999;
left: 50%;
padding:10px;
position: absolute;
width: 500px;
margin-left: -250px;
top:100px;
}
</style>
<apex:form >
<apex:pageBlock >
<apex:commandButton action="{!openPopup}" value="Open Popup" />
<apex:outputPanel id="tstpopup" rendered="{!showPopup}">
<apex:outputPanel styleClass="popupBackground" layout="block" />
<apex:outputPanel styleClass="custPopup" layout="block" >
<center>
Hello this is Custom pop-Up<BR></BR>
<apex:commandButton value="Save" action="{!Cancel}" />
<apex:commandButton value="Cancel" action="{!Cancel}" />
</center>
</apex:outputPanel>
</apex:outputPanel>
</apex:pageBlock>
</apex:form>
</apex:page>
Please let us know if this will help you
Thanks
Amit Chaudhary