Taking values from a form without sending it...

 
<table>
<tr><td>
<input name="street" id="street" size="30" maxlength="100" />
</td><tr>
<tr><td>
<input name="city" id="city" size="30" maxlength="100" />
</td></tr>
</table>

<a href="#" onClick="showmenow('formurba','visible')">Extra details</a>

function showmenow(object,val) { 
document.getElementById(object).style.visibility = val; 
var local = document.getElementById("SubCat");
var street = document.getElementById("street");
var city = document.getElementById("city");
street2.value = street.value;
    city2.value = city.value;
}

<div id="formurba">
<SCRIPT Language="JavaScript">
document.write("Street name :" + street + "Cuty name : " + city)
</SCRIPT>
<input type="hidden" name="street2" id="street2" value="">
<input type="hidden" name="city2" id="city2" value="">
</div>

document.getElementById("formurba").innerHTML = "Street name :" + street + "Cuty name : " + city;

function showmenow(object,val) { 
document.getElementById(object).style.visibility = val; 
var local = document.getElementById("SubCat");
var street = document.getElementById("street");
var city = document.getElementById("city");
street2.value = street.value;
    city2.value = city.value;
var h = document.getElementById("formurba").innerHTML;
h = "Street name :" + street + "Cuty name : " + city + h; }