function IsNumber(sText){
   var ValidChars = "1234567890";
   var IsValid = true;
   var Char;
 
   for (i = 0; i < sText.length && IsValid == true; i++) 
   { 
	  Char = sText.charAt(i); 
	  if (ValidChars.indexOf(Char) == -1) 
		 IsValid = false;
	}
   return IsValid; 
}
//__________________________________________________________________________  	
function IsValidEmail(str)
{ if (str+"" == "undefined" || str+"" == "null" || str+"" == "") return false;
  var isValid = true;
  str += "";
  var namestr = str.substring(0, str.indexOf("@"));
  var domainstr = str.substring(str.indexOf("@")+1, str.length);
  if (IsBlank(str) || (namestr.length == 0) || (domainstr.indexOf(".") <= 0) || (domainstr.indexOf("@") != -1) || !IsAlpha(str.charAt(str.length-1))) isValid = false;   
  return isValid;
}
//__________________________________________________________________________

function IsBlank(str) 
{ return (IsNull(str) || IsUndef(str) || (str+""==""));
} 
//__________________________________________________________________________

function IsNull(val) 
{ return (val+""=="null");
}
//__________________________________________________________________________

function IsUndef(val) 
{ return (val+""=="undefined");
}
//__________________________________________________________________________

function IsAlpha(str) 
{ if (str+"" == "undefined" || str+"" == "null" || str+"" == "") return false;
  var isValid = true;
  str += "";
  for (i = 0; i < str.length; i++) 
     { if (!(((str.charAt(i) >= "a") && (str.charAt(i) <= "z")) || ((str.charAt(i) >= "A") && (str.charAt(i) <= "Z")))) 
      	{ isValid = false;
          break;
      	}
     }   
  return isValid;
}
//__________________________________________________________________________

function ForceEntry(objField, FieldName)
{ var strField = new String(objField.value);
  if (isWhitespace(strField)) 
    { alert("You need to enter your " + FieldName);
	  objField.focus();
      return false;
	}
  return true;
}
//__________________________________________________________________________


function NameLength(objField, FieldName)
{ var strField = new String(objField.value);
  if (strField.length>20) 
    { alert("Character Length longer than 20 \r\n" + FieldName);
	  objField.focus();
      return false;
	}
  return true;
}
//__________________________________________________________________________
function isEmpty(strText)
{ return ((strText == null) || (strText.length == 0))
}
//__________________________________________________________________________

function isWhitespace(strText)
{ var i;
  var strChar;
  var whitespace = " \t\n\r";
  if (isEmpty(strText)) return true;
  for (i = 0; i < strText.length; i++)
     { strChar = strText.charAt(i);
	   if (whitespace.indexOf(strChar) == -1) return false;
     }
  return true;
}
//__________________________________________________________________________