function ChangeAction(ival)
{
    var oktoproceed = true; 
    var errortext = '';
    var str = '';
    var con = '';
    
    
    // VALID EMAIL
    switch(ival)
    {
        case 1: 
            str = document.checkoutform.email.value;
            con = document.checkoutform.confirmemail.value;
            break;
        case 2:
            str = document.detailsform.F_Email.value;
            con = str;
            break;
        default:
            str = "";
            break;
    }
     
	if (isValidEmail(str))
	{
	} else {
        errortext=errortext+'You must enter a valid Email Address.\n';
	    oktoproceed=false;
	}

    if (str!=con) {
	    errortext=errortext+'Please check your email address. The \'confirm\' email address does not match your actual email address.\n';
	    oktoproceed=false;
	}


    // VALID PRICE
    switch(ival)
    {
        case 1: 
            str = document.checkoutform.PricePaid.value;
            break;
        case 2:
            str = document.detailsform.F_PricePaid.value;
            break;
        default:
            str = "";
            break;
    }

	if (str=="" || isCurrency(str))
	{
	} else {
	    errortext=errortext+'You must enter a valid Purchase Price.\n';
	    oktoproceed=false;
	}


    // VALID DATE
    if(ival==1)
    {
        str = document.checkoutform.PurchaseDate.value;
	    if (isValidDate(str))
	    {
	    } else {
            errortext=errortext+'You must enter a valid Purchase Date in dd/mm/yyyy format.\n';
	        oktoproceed=false;
	    }
    }
     



  	// SHOW VALIDATION MESSAGES
    if (errortext!='') {
	    alert(errortext);
	}

    return oktoproceed;
}



function isValidEmail(emailAddress) 
{
    var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
    return re.test(emailAddress);
}

function isCurrency(str) 
{ 
    var re = /^\d+(\.\d{2}){0,1}$/
    return re.test( str ); 
} 

function isValidDate(str)
{
    var re = /^(0[1-9]|[12][0-9]|3[01])[/](0[1-9]|1[012])[/](19|20)\d\d$/
    return re.test( str ); 
}