function clearText(field){
    if (field.defaultValue == field.value) field.value = '';
    else if (field.value == '') field.value = field.defaultValue;

}

function clickclear(thisfield, defaulttext, color) {
	if (thisfield.value == defaulttext) {
		thisfield.value = "";
		if (!color) {
			color = "000";
		}
		thisfield.style.color = "#" + color;
	}
}

function validate_email(field)
{
with (field)
  {
  apos=value.indexOf("@");
  dotpos=value.lastIndexOf(".");
  if (apos<1||dotpos-apos<2)
    {return false;}
  else {return true;}
  }
}

function validateCreditCard(s) {
var v = "0123456789";
var w = "";
for (var i=0; i < s.length; i++) {
x = s.charAt(i);
if (v.indexOf(x,0) != -1)
w += x;
}
var j = w.length / 2;
if (j < 6.5 || j > 8 || j == 7) return false;
var k = Math.floor(j);
var m = Math.ceil(j) - k;
var c = 0;
for (var i=0; i<k; i++) {
a = w.charAt(i*2+m) * 2;
c += a > 9 ? Math.floor(a/10 + a%10) : a;
}
for (var i=0; i<k+m; i++) c += w.charAt(i*2+1-m) * 1;
return (c%10 == 0);
}