// JavaScript Document
//kiem tra cac loi
function loidetrong(o,loi)
{
	with (o)
	{
		re = /\w/
		str = re.exec(value)
		if (value==null||value==""||value==""||str==null)
			{alert(loi);return true}
		else {return false}
	}
}
function loiemail(o,loi)
{
	with (o)
	{
		apos=value.indexOf("@");
		dotpos=value.lastIndexOf(".");
		dotdua=value.indexOf("..");
		len=value.length -1;
		if (apos<1||(dotpos<=apos+1)||(dotpos==len)||dotdua!=-1) 
		{
			alert(loi);return true
		}
		else {return false}
	}
}
function loiso(o,loi)
{
	with(o)	
	{
		if (isNaN(value))
		{alert(loi);return true}
		else {return false}
	}
}
function loiwebsite(o,loi)
{
	with(o)
	{
		apos=value.indexOf("www");
		apos1=value.indexOf("http://www");
		dotpos2=value.indexOf(".") ;
		dotpos=value.lastIndexOf(".");
		dotdua=value.indexOf("..")
		len=value.length-1;
		if ((apos!=0&& apos1!=0)||dotpos==len||dotpos2==dotpos||dotdua!=-1)
		{
			alert(loi);return true
		}
		else {return false}
	}
}