Calendar.setup=function(params){

    function param_default(pname,def){

        if(typeof params[pname]=="undefined"){

            params[pname]=def;

        }

    };



param_default("inputField",null);

    param_default("displayArea",null);

    param_default("button",null);

    param_default("eventName","click");

    param_default("ifFormat","%Y/%m/%d");

    param_default("daFormat","%Y/%m/%d");

    param_default("singleClick",true);

    param_default("disableFunc",null);

    param_default("dateStatusFunc",params["disableFunc"]);

    param_default("firstDay",1);

    param_default("align","Br");

    param_default("range",[1900,2999]);

    param_default("weekNumbers",false);

    param_default("flat",null);

    param_default("flatCallback",null);

    param_default("onSelect",null);

    param_default("onClose",null);

    param_default("onUpdate",null);

    param_default("date",null);

    param_default("showsTime",false);

    param_default("timeFormat","24");

    param_default("electric",true);

    param_default("step",2);

    param_default("position",null);

    param_default("cache",false);

    param_default("showOthers",false);

    var tmp=["inputField","displayArea","button"];

    for(var i in tmp){

    if(typeof params[tmp[i]]=="string"){

        params[tmp[i]]=document.getElementById(params[tmp[i]]);

    }

}

if(!(params.flat||params.inputField||params.displayArea||params.button)){

    alert("Calendar.setup:\n  Nothing to setup (no fields found).  Please check your code");

    return false;

}

function onSelect(cal){

    var p=cal.params;

    var update=(cal.dateClicked||p.electric);

    if(update&&p.flat){

        if(typeof p.flatCallback=="function")p.flatCallback(cal);else alert("No flatCallback given -- doing nothing.");

        return false;

    }

    if(update&&p.inputField){

        p.inputField.value=cal.date.print(p.ifFormat);

        if(typeof p.inputField.onchange=="function")p.inputField.onchange();

    }

    if(update&&p.displayArea)p.displayArea.innerHTML=cal.date.print(p.daFormat);

    if(update&&p.singleClick&&cal.dateClicked)cal.callCloseHandler();

    if(update&&typeof p.onUpdate=="function")p.onUpdate(cal);

};



if(params.flat!=null){

    if(typeof params.flat=="string")params.flat=document.getElementById(params.flat);

    if(!params.flat){

        alert("Calendar.setup:\n  Flat specified but can't find parent.");

        return false;

    }

    var cal=new Calendar(params.firstDay,params.date,params.onSelect||onSelect);

    cal.showsTime=params.showsTime;

    cal.time24=(params.timeFormat=="24");

    cal.params=params;

    cal.weekNumbers=params.weekNumbers;

    cal.setRange(params.range[0],params.range[1]);

    cal.setDateStatusHandler(params.dateStatusFunc);

    cal.create(params.flat);

    cal.show();

    return false;

}

var triggerEl=params.button||params.displayArea||params.inputField;

triggerEl["on"+params.eventName]=function(){

    var dateEl=params.inputField||params.displayArea;

    var dateFmt=params.inputField?params.ifFormat:params.daFormat;

    var mustCreate=false;

    var cal=window.calendar;

    if(!(cal&&params.cache)){

        window.calendar=cal=new Calendar(params.firstDay,params.date,params.onSelect||onSelect,params.onClose||function(cal){

            cal.hide();

        });

        cal.showsTime=params.showsTime;

        cal.time24=(params.timeFormat=="24");

        cal.weekNumbers=params.weekNumbers;

        mustCreate=true;

    }else{

        if(params.date)cal.setDate(params.date);

        cal.hide();

    }

    cal.showsOtherMonths=params.showOthers;

    cal.yearStep=params.step;

    cal.setRange(params.range[0],params.range[1]);

    cal.params=params;

    cal.setDateStatusHandler(params.dateStatusFunc);

    cal.setDateFormat(dateFmt);

    if(mustCreate)cal.create();

    cal.parseDate(dateEl.value||dateEl.innerHTML);

    cal.refresh();

    if(!params.position)cal.showAtElement(params.button||params.displayArea||params.inputField,params.align);else cal.showAt(params.position[0],params.position[1]);

    return false;

};



};