You just put below code in your template style :
// Checked for Display Div Start
function fnchecked(blnchecked){
if(blnchecked){
document.getElementById(“webAddress”).style.display = “block”;
document.getElementById(“wwebAddress”).style.display = “block”;
document.getElementById(“wwebAddress”).style.height = “20px”;
//document.getElementById(“customers_wwebaddress”).value = “”;
}
else{
document.getElementById(“webAddress”).style.display = “none”;
document.getElementById(“wwebAddress”).value = “”;
document.getElementById(“wwebAddress”).style.display = “none”;
document.getElementById(“wwebAddress”).style.height = “0.1em”;
}
}
Finally call that function below textbox inside :
<input type=”text” onclick=”fnchecked(this.checked);” />