function isempty(s)
{	
	return ((s==null)||(s.length=0))
}
function iswhitespace(s)
{    
    var whitespace="\t\n\r";
	if (isempty(s))return true;
	var i;
	for (i=0;i<s.length;i++)
	{
		var c=s.charAt(i);
		if (whitespace.indexOf(s)!=-1)
			continue;
		else
			return false;
	}
	return true;
}
function isemail(s)
{
	var i=1;
	var slength=s.length;
	while ((i<slength)&&(s.charAt(i)!="@"))
	{
		i++;
	}
	if ((i>slength)||(s.charAt(i)!="@"))return false;
	else i+=2;
	while((i<slength)&&(s.charAt(i)!="."))
	{
		i++;
	}
	if((i>=slength-1)||(s.charAt(i)!="."))return false;
	else return true;
}
function warnempty(thefield,s)
{
	alert(s);
	thefield.focus();
	return false;
}
function warninvalid(thefield,s)
{
	alert(s);
	thefield.focus();
	thefield.select();
	return false;
}
function checkstring(thefield,s)
{
	if(thefield==null)return true;
	if(iswhitespace(thefield.value))
		return warnempty(thefield,s);
	else return true;
}
function checkemail(thefield,s)
{
	if(!isemail(thefield.value))
		return warninvalid(thefield,s);
	else return true;
}
function isnumber(s)
{
	var digits="0123456789";
	var i=0;
	var slength=s.length;
	while((i<slength))
	{
		var c=s.charAt(i);
		if(digits.indexOf(c)==-1) return false;
		i++;
	}
	return true;
}
function checknumber(thefield,s)
{
	if(!isnumber(thefield.value))return false;
	if(iswhitespace(thefield.value))
		return warnempty(thefield,s);
	else return true;
}
function checkzip(thefield,s)
{
	var ss=thefield.value;
	var digits="0123456789"
	var i=0;
	var slength=ss.lenght;
	if(slength<6)
		return warninvalid(thefield,s);
	while ((i<slength))
	{
		var c=ss.charAt(i);
		if(digits.indexOf(c)==-1)
			return warninvalid(thefield,s);
		i++;
	}
	return true;
}
function checkphone(thefield,s)
{
	var ss=thefield.value;
	var digits="0123456789"
	var i=0;
	var slength=ss.length;
	while ((i<slength))
	{
		var c=ss.charAt(i);
		if(digits.indexOf(c)==-1)
			return warninvalid(thefield,s);
		i++;
	}
	c="--";
	if(ss.indexOf(c)!=-1)
		return warninvalid(thefield,s);
	return true;
}
function checkpassword(thefield)
{
	if(thefield.value.length<4)
	{
		alert("ÃÜÂ볤¶ÈСÓÚ4");
		thefield.focus();
		return false;
	}
	else return true;
}
function checkfigure(thefield,s)
{
	var vv,ww,xx;
	vv=thefield.value;
	var ipos=vv.indexOf(".");
	if(ipos==0)vv="0"+vv;
	if(ipos==(vv.length-1)) vv=vv+"0";
		xx=parsefloat(vv);
		ww=xx.tostring(10);
		var i=vv.length-ww.length;
		var j=0;
		if(i>0) 
		{
			ipos=ww.indexOf(".");
			if(ipos==-1)
			{
				ww=ww+".";
				i=i-1;
			}
			for(j=0;j<i;j++)
				ww=ww+"0";
		}
		if(ww!=vv)
			return warninvalid(thefield,s);
		return true;
}