function isText(field, fieldname) 
{
  var field_val = trim(field.value);
  if(field_val == "") 
  {
    alert(fieldname + " field can not be left empty!");
	field.focus();
	field.select();
	return false;
  }
  return true;
} //isText

function isNum(field,fieldname) 
{
  //Checks for if the value of the field is numerical
  var valid = "0123456789";
  var ok = "yes";
  var temp;
  for (var i=0; i<field.value.length; i++) 
  {
	temp = "" + field.value.substring(i, i+1);
	if (valid.indexOf(temp) == "-1" || valid.value == "" ) ok = "no";
  }
  if ((ok == "no") || (field.value=="")) 
  {
	alert(fieldname + "www");
	field.value="0";
	field.focus();
	field.select();
	return false;
  }
  return true;
} // isNum

function isNumber()
{	
  //Checks for enter pressed a number
  //onKeyPress="return isNumber()"
  if ((event.keyCode < 58) && (event.keyCode > 47)) 
	   event.returnValue = true;
  else event.returnValue = false;	
}

function isEmail(field)
{
  var string = trim(field.value);

  if (string == "" || string.indexOf ('@',0) == -1 || string.indexOf ('.',0) == -1 || string.indexOf ('@', string.indexOf('@',0) + 1) != -1 || string.indexOf (',',0) != -1 || string.indexOf (';',0) != -1 || string.indexOf (':',0) != -1 || string.substring(0,1) == "@" || string.substring(0,1) == ".") 
  {
    alert("Please enter your e-mail address correctly!");
	field.select();
	field.focus();
    return false; 
  }
  return true;
}

function trim(string)
{
  string = LTrim(string);
  return RTrim(string);
}

function RTrim(string)
{
  while(string.charAt((string.length -1)) == " ")
  {
    string = string.substring(0, string.length-1);
  }
  return string;
}

function LTrim(string)
{
  while(string.charAt(0) == " ")
  {
    string = string.replace(string.charAt(0), "");
  }
  return string;
}