function addLoadEvent(func)
{
    var oldOnLoad = window.onload;
    if(typeof window.onload != 'function')
    {
        window.onload = func;
    }
    else
    {
        window.onload= function()
        {
            oldOnLoad();
            func();
        }
    }
}

function isValidEmail(email) {
		var regEx =/\w{1,}[@]\w{1,}([.](\w{1,})){1,2}$/g,i; 
		if (!regEx.test(email)) {
			return false;
		}
		else
		{
		return true;
		}
	}  
	
function isNaturalNumber(number)
{
	if(isNaN(number) || number=="0")
	{
		return false;
	}
	else
	{
		return true;
	}
}