function resetField(element)
{
	if(element.value.length==0){
		element.value="Cerca nel sito";
	}
}

function clearField(element)
{
	if( element.value=="Cerca nel sito")
	{
		element.value="";
	}
}

function isNumeric(sText)
{
    var ValidChars = "0123456789.,";
    var IsNumber=true;
    var Char;

    for (i = 0; i < sText.length && IsNumber == true; i++)
    {
            Char = sText.charAt(i);
            if (ValidChars.indexOf(Char) == -1)
            {
                    IsNumber = false;
            }
    }

    return IsNumber;
}

function isset(variable_name) 
{
	try 
    {
        if (typeof(eval(variable_name)) != "undefined")
        if (eval(variable_name) != null)
        return true;
    } 
    catch(e) { }
    return false;
}