function ddCommand(url, command, fields, callback)
{
    var param="";
    
    if (fields==null) {
    
        param="v="+encodeURI(command)+
                "&sid="+Math.random();
                
        ddMakePostRequest(url, param, callback);
        
    } else {
    
        //alert(fields.length);
        
        if (fields.length > 0) {
        
            //alert(document.getElementById(fields[0]).type);
            
            var ajaxfields=""; //""+fields[0]+"="+document.getElementById(fields[0]).value;
        
            //alert(fields.length);
            
            var curStr="";
            var first=true;
            for (var t=0;t<fields.length;t++){
                
                //alert(t+"-"+fields[t]);
                
                //alert();
                
                if (document.getElementById(fields[t]).type=="checkbox") {
                
                    if (document.getElementById(fields[t]).checked)
                    
                        curStr="on";
                        
                    else
                    
                        curStr="off";
                        
                } else {
                
                    curStr=document.getElementById(fields[t]).value;
                    
                    if (curStr.indexOf("`")!=-1) {
                    
                        alert("what the fuck are you trying to do?");
                        return;
                    
                    }
                    
                }
                
                if (first==true) {
                
                    ajaxfields=ajaxfields+fields[t]+"="+curStr;
                    first=false;
                    
                } else
                
                    ajaxfields=ajaxfields+"`"+fields[t]+"="+curStr;
                
            }
            
            param="v="+encodeURI(command)+
                    "&f="+encodeURI(ajaxfields)+
                    "&sid="+Math.random();
                    
            //alert(param);
                    
            //alert("command-fields");
            ddMakePostRequest(url, param, callback);
                    
        } else {
        
            alert("Sorry, there was a server error...");
        
        }
    
    }

}


//this function is option, and provides a generic way to update an
//element
function ddCommandDone(id)
{
    var response="";
    if (xhttp.readyState==4 || xhttp.readyState=="complete"){
        
        response=xhttp.responseText;

        //alert(response);
        
        var cBlock=response.split("(~)");
        
        if (cBlock[0]=="ok") {
        
            document.getElementById(id).innerHTML=cBlock[1];
            
        } else {
        
            if (response.length==0)
                alert("there was a server error.  empty reply.  please try again.");
            else {
            
                if (response.match("( ! )")!=null) {
                    
                    document.getElementById(id).innerHTML="<div style=\"background:darkred; color:white; padding:10px;\">"+response+"</div>";
                    
                    return;
                    
                }
                
                if (cBlock[0]=="debug") {
                
                    alert(response);
                    document.getElementById("debug").innerHTML="<div style=\"background:darkred; color:white; padding:10px;\"><pre>"+response+"</pre></div>";
                    
                    return;
                
                }    
                    
                alert("server error:\n\n"+response);
                
            }
            
        }
        
    }
    
}

function ddMakePostRequest(url, param, callback)
{
    
    xhttp = false;
    if (window.XMLHttpRequest) 
    { // Mozilla, Safari,...
        xhttp = new XMLHttpRequest();
        if (xhttp.overrideMimeType) 
        {
            // set type accordingly to anticipated content type
            //http_request.overrideMimeType("text/xml");
            xhttp.overrideMimeType("text/html");
        }
    } 
    else if (window.ActiveXObject) 
    { // IE
        try 
        {
            xhttp = new ActiveXObject("Msxml2.XMLHTTP");
        } 
        catch (e)
        {
            try 
            {
                xhttp = new ActiveXObject("Microsoft.XMLHTTP");
            } 
            catch (e) 
            {}
        }
    }
    if (!xhttp) 
    {
        alert("Cannot create XMLHTTP instance");
        return false;
    }
    
    //alert (param);
    
    xhttp.onreadystatechange = callback;//bodychangeready;
    xhttp.open("POST", url, true);
    xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    xhttp.setRequestHeader("Content-length", param.length);
    xhttp.setRequestHeader("Connection", "close");
    xhttp.send(param);
    
}