Seperator for passing variables via url string

Seperator for passing variables via url string

here is my nonworking example (between forms) 

openUrl("#Form:Client_Form_GC_CL" + "?TZ2CF_Address_1=" + input.TZ2PF_Address_1 & "?TZ2CF_Address_2=" + input.TZ2PF_Address_2, "Popup window", "height=400,width=400");


NOTE the single ampersand does not work as a separator between fields...what does?. Help Please

Thanks

Larry