function isValid() 
{
var string = payOnline.amount.value;
string = string.replace(/^  */, "").replace(/  *$/, "");
if (string == "")
{
alert("Please enter an amount.");
payOnline.amount.focus();
return false;
}
var match = string.search(/^[0-9]*(\.[0-9]{0,2})?$/);
if (match == -1)
{
alert("Please enter a valid amount.");
payOnline.amount.select();
payOnline.amount.focus();
return false;
}
payOnline.amount.value = string;
payOnline.amount.select();
return true;
}