function get_elem(el) {return document.getElementById(el);}

function get_all_elements(prefix) {
    i=1; count=0;
    while (get_elem(prefix+'_'+i) != null) {i++;}
    return i;
}

var ajax_request = false;

if      (window.XMLHttpRequest) {ajax_request = new XMLHttpRequest();                   }
else if (window.ActiveXObject)  {ajax_request = new ActiveXObject("Microsoft.XMLHTTP"); }

/* Отправка POST'ом */
function ajax_post(file, data, div) {
   if (ajax_request) {
     var obj=get_elem(div);

     ajax_request.open("POST", file);
     ajax_request.setRequestHeader("Content-Type","application/x-www-form-urlencoded; charset=UTF-8");

     ajax_request.onreadystatechange = function() {
        if (ajax_request.readyState==4 && ajax_request.status==200) {
            obj.innerHTML = ajax_request.responseText;
        }
     }
     ajax_request.send(data);
   }
}

/* Отправка GET'ом */
function ajax_get(data, div) {
   if (ajax_request) {
     var obj=get_elem(div);
     ajax_request.open("GET", data);
     ajax_request.onreadystatechange = function() {
        if (ajax_request.readyState==4 && ajax_request.status==200) {
            obj.innerHTML = ajax_request.responseText;
        }
     }
     ajax_request.send(null);
   }
}

/* Отправка GET'ом */
function ajax_get_send(data) {
   if (ajax_request) {
     ajax_request.open("GET", data);
     ajax_request.onreadystatechange = function() {
     }
     ajax_request.send(null);
   }
}
/* Отправка с формы */
function ajax_post_form(form_id,file,div) {
    var theform;
    var post_result="";
        if (window.navigator.appName.toLowerCase().indexOf("microsoft") > -1) {
            theform = document.getElementById(form_id);
        }
        else {
            theform = document.forms[form_id];
        }
        for (i=0; i<theform.elements.length; i++) {
           with (theform) {
               post_result += (elements[i].name+'='+elements[i].value+'&');
               /* alert (elements[i].name+' = '+elements[i].value); */
           }
        }
        ajax_post(file,post_result,div);
        /*alert(post_result);*/
}