How to pass value to another page

Hi,

 I want to pass a email  txtbox value from page which is created in asp.net using master page(containing form runat=server ),  to anothet page which is created in php which is placed on another server.

email textbox  and submit buttons are  html controls.

on submit I want to open popup page which is my target of posting data.

 

I have used this javascript code on click on button ,

 

function MM_openBrWindow(theURL,winName,features) { 
window.open(theURL,winName,features);
}

function checkEmail(subscribeEmail) {

if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(subscribeEmail.v ...