// Prints the page

function printthis() {
window.print();
}

//Validates the login form


function validateFormOnSubmit(theForm) {
var reason = "";
	reason += validateEmpty(theForm.reg);
	reason += validateEmpty(theForm.pass);
      
  if (reason != "") {
    alert("Please fill in your:\n" + reason);
    return false;
  }

  return true;
}

function validateCalc(theForm) {
var reason = "";
	reason += validateEmpty(theForm.population);
	reason += validateEmpty(theForm.sample_size);
	reason += validateLessThan(theForm.sample_size,theForm.population);
      
  if (reason != "") {
    alert("Please fill in your:\n" + reason);
    return false;
  }

  xmlhttpPost('calculator.asp', 'calc', 'confcalc_rslts', '<img src=\'img\ajaxloader.gif\'>'); 
  return false;
}

function validateEmpty(fld) {
    var error = "";
 
    if (fld.value.length == 0) {
        fld.style.background = 'Yellow'; 
        error = fld.name + "\n";
    } else {
        fld.style.background = 'White';
    }
    return error;  
}

function validateLessThan(fld,otherfld) {
    var error = "";
	var value1 = parseInt(fld.value);
	var value2 = parseInt(otherfld.value);
 
    if (value2 < value1) {
        error = "Sample size must be smaller\n";
    }
    return error;  
}

// Show/reveal script
function toggle_visibility(id) {
   var e = document.getElementById(id);
   if(e.style.display == 'block')
	  e.style.display = 'none';
   else
	  e.style.display = 'block';
	  	  
}

function xmlhttpPost(strURL,formname,responsediv,responsemsg) {
    var xmlHttpReq = false;
    var self = this;
    // Xhr per Mozilla/Safari/Ie7
    if (window.XMLHttpRequest) {
        self.xmlHttpReq = new XMLHttpRequest();
    }
    // per tutte le altre versioni di IE
    else if (window.ActiveXObject) {
        self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
    }
    self.xmlHttpReq.open('POST', strURL, true);
    self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    self.xmlHttpReq.onreadystatechange = function() {
        if (self.xmlHttpReq.readyState == 4) {
			// Quando pronta, visualizzo la risposta del form
            updatepage(self.xmlHttpReq.responseText,responsediv);
        }
		else{
			// In attesa della risposta del form visualizzo il msg di attesa
			updatepage(responsemsg,responsediv);

		}
    }
    self.xmlHttpReq.send(getquerystring(formname));
}



function getquerystring(formname) {
    var form = document.forms[formname];
	var qstr = "";

    function GetElemValue(name, value) {
        qstr += (qstr.length > 0 ? "&" : "")
            + escape(name).replace(/\+/g, "%2B") + "="
            + escape(value ? value : "").replace(/\+/g, "%2B");
			//+ escape(value ? value : "").replace(/\n/g, "%0D");
    }
	
	var elemArray = form.elements;
    for (var i = 0; i < elemArray.length; i++) {
        var element = elemArray[i];
        var elemType = element.type.toUpperCase();
        var elemName = element.name;
        if (elemName) {
            if (elemType == "TEXT"
                    || elemType == "TEXTAREA"
                    || elemType == "PASSWORD"
					|| elemType == "BUTTON"
					|| elemType == "RESET"
					|| elemType == "SUBMIT"
					|| elemType == "FILE"
					|| elemType == "IMAGE"
                    || elemType == "HIDDEN")
                GetElemValue(elemName, element.value);
            else if (elemType == "CHECKBOX" && element.checked)
                GetElemValue(elemName, 
                    element.value ? element.value : "On");
            else if (elemType == "RADIO" && element.checked)
                GetElemValue(elemName, element.value);
            else if (elemType.indexOf("SELECT") != -1)
                for (var j = 0; j < element.options.length; j++) {
                    var option = element.options[j];
                    if (option.selected)
                        GetElemValue(elemName,
                            option.value ? option.value : option.text);
                }
        }
    }
    return qstr;
}
function updatepage(str,responsediv){
	document.getElementById(responsediv).className = "showResults";
    document.getElementById(responsediv).innerHTML = str;
}