How to find the checkbox checked are not in javascript using in asp.net

var chkStatus1 = document.getElementById("chkbutton1");
var chkStatus2 = document.getElementById("chkbutton2");

if (chkStatus1.checked) {
    // do your implementation for if part
}
else if(chkStatus2.checked)
{
   // do your implementation for else if part for checkbox2
}
else if(chkStatus2.checked && chkStatus2.checked)
{
   // do your implementation when two chechbox status is checked.
}
else
{
   // do your implementation for else part.
}