function getRandomCover(strImg,lengthArr,dirCover){

    var arrImage = new Array(lengthArr);
    
    arrImage = strImg.split(",");
    
    //alert(arrImage);
    
    var founded = getElementHandle('coverImage');
    
    var randomNumber = Math.round(Math.random()*(arrImage.length-1));
    
    founded.src = dirCover+arrImage[randomNumber];
    
}

function validateMailForm(addORrem){
	
	var formHandle = getElementHandle('formML');
	var stringError = "";
    
	stringError += checkEmptyField(formHandle.address.value,"E-mail");
	stringError += checkMailField(formHandle.address.value,"E-mail");

	if(stringError != ""){
		alert(stringError);
	}else{
		formHandle.addOrRemove.value = addORrem;
		formHandle.submit();
	}
    
}

function validateLoginForm(){
	
	var formHandle = getElementHandle('loginForm');
	var stringError = "";
    
	stringError += checkEmptyField(formHandle.user.value,"User Name");
	//stringError += checkMailField(formHandle.pawd.value,"Password");

	if(stringError != ""){
		alert(stringError);
	}else{
		formHandle.submit();
	}
    
}

function validateUploadForm(){
	
	var formHandle = getElementHandle('uploadForm');
	var stringError = "";
	//alert(formHandle.fileUp.value);
	
	stringError += checkEmptyField(formHandle.address.value,"E-mail");
	stringError += checkMailField(formHandle.address.value,"E-mail");
	stringError += checkEmptyField(formHandle.fileUp.value,"File");
	stringError += checkEmptyField(formHandle.description.value,"Description");

	if(stringError != ""){
		alert(stringError);
	}else{
		formHandle.submit();
	}
    
}

function checkEmptyField(theElementValue,nameField){
    return theElementValue == "" ? "WARNING: "+nameField+" field is empty!\n": "" ;
}

function checkDataField(theElementValue,nameField){
    var tempArr = new Array(3); 
    
    tempArr = theElementValue.split("/");
    
    if(tempArr.length == 3){
        for(i=0;i<tempArr.length;i++){
            tempArr[i] = parseInt(tempArr[i]);

        }
        
        return isNaN(tempArr[0]) == true || isNaN(tempArr[1]) == true || isNaN(tempArr[2]) == true ||  tempArr[0] <= 0 || tempArr[0] > 31 || tempArr[1] < 1 || tempArr[1] > 12 || tempArr[2] < 1900 || tempArr[2] > 2100 ? "Campo "+nameField+" scritto in modo errato!\n" : "";   
    }else{
        return "Campo "+nameField+" scritto in modo errato!\n";
    }
}

function checkMailField(theElementValue,nameField){
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	return filter.test(theElementValue) == false ? "WARNING: "+nameField+" field is not valid!\n" : "" ;
}


function changeBackgroundColorOfDiv(thisDiv){
    var foundedDiv = getElementHandle(thisDiv);
    
    if(foundedDiv.style.background == ""){
        foundedDiv.style.background = "#8DAAB0";
    }else{
        foundedDiv.style.background = "";
    }
    

}


function getElementHandle(idObject){
	
	//document object model dection
	if (document.all){
		var divElement = document.all(idObject);
	}else if (document.layers){
		var divElement = document.layers[idObject];
	}else if (document.getElementById){ 
		var divElement = document.getElementById(idObject);
	}
	return divElement;
}