var arrTopBannerImgs = new Array();
var arrTopBannerLinks = new Array();

var arrBottomBannerImgs = new Array();
var arrBottomBannerLinks = new Array();

var progImgs = new Array();
var currentAd = 0; 
var currentBottomAd = 0;
      
 function cycleTopBanner() 
 {
      currentAd++;
      if (currentAd == arrTopBannerImgs.length) 
      {
        currentAd=0;
      }

    document.topBanner.src = arrTopBannerImgs[currentAd].src;
    document.getElementById("topBannerLink").href = arrTopBannerLinks[currentAd];
    setTimeout("cycleTopBanner()",10 * 1000);    
 }
 
 function cycleBottomBanner() 
 {
      currentBottomAd++;
      if (currentBottomAd == arrBottomBannerImgs.length) 
      {
        currentBottomAd = 0;
      }

    document.bottomBanner.src = arrBottomBannerImgs[currentBottomAd].src;
    document.getElementById("bottomBannerLink").href = arrBottomBannerLinks[currentBottomAd];
    setTimeout("cycleBottomBanner()",10 * 1000);    
 }


function validateSendFriend()
{
    var txtFriendEmail = document.SendFriend.txtFriendEmail;
    var txtName = document.SendFriend.txtName;
    var txtEmail = document.SendFriend.txtEmail;

    
    var isValid = true;
    document.getElementById("errMsg").innerHTML = "";
    
    if(txtFriendEmail.value == "")
    {
        document.getElementById("errMsg").innerHTML = "Friend's email address cannot be empty";  
        return false;  
    }
    else if(validateEmail(txtFriendEmail.value) == false)
    {
        document.getElementById("errMsg").innerHTML = "Friend's email address is not valid, must be of the form mail@email.com";  
        return false;  
    }
    else if(txtName.value == "")
    {
        document.getElementById("errMsg").innerHTML = "Your name cannot be empty";  
       return false;  
    }
    else if(txtEmail.value == "")
    {
        document.getElementById("errMsg").innerHTML = "Your email address cannot be empty";  
        return false;  
    }
    else if(validateEmail(txtEmail.value) == false)
    {
        document.getElementById("errMsg").innerHTML = "Your email address is not valid, must be of the form mail@email.com";  
        return false;  
    }
    
    return true;
}

function validateEmail(strEmail) 
{
	var pattern=/^([a-zA-Z0-9_.-])+@([a-zA-Z0-9_.-])+\.([a-zA-Z])+([a-zA-Z])+/;
    if(pattern.test(strEmail)){         
		return true;
    }else{   
		return false;
    }
}

function showProgrammeImg(currImgIndex)
{
	document.images.currProgImg.src = progImgs[currImgIndex].src;
}