//===================================================================
//Check if a field is left empty. Called by validateForm() function.
//===================================================================
function emptyField(str)
{
 if (str.length == 0) return true;
 for (var i = 0; i < str.length; i++)
    {
      var ch = str.charAt(i); 
      if (ch != ' ' && ch != '\t') return false;
     }
 
 return true;
}
function isLetter(c)
{
	if(((c >= "a") && (c <= "z")) || ((c >= "A") && (c <= "Z")))
	{
		return true;
	}
	else
	{
		return false;
	}
}

function isDigit(c)
{
	return ((c >= "0") && (c <= "9"));
}

function isInteger(s)
{
	var i;
	for(i=0; i < s.length; i++)
	{
		var c = s.charAt(i);
		if(!isDigit(c)) return false;	
	}
	return true; 	// All characters are numbers
}

function isAlphanumeric(s)
{
	var i;
	var bNumeric = false;
	var bAlphabetic = false;

	for(i=0; i < s.length; i ++)
	{
		var c = s.charAt(i);
		if(isLetter(c))
		{
			bAlphabetic = true;
		}		
		
		if(isDigit(c))
		{
			bNumeric = true;
		}
	}

	if((bNumeric == true) && (bAlphabetic == true))
	{
		return true;
	}
	else
	{
		return false;
	}
}

function isValidInteger(s)
{
	var i;
	for(i=0; i < s.length; i++)
	{
		var c = s.charAt(i);

		if(i>=1)
		{	// There shouldnt be a negative sign unless it is
			// in front of the number
			if(c=="-") return false;
		}

		if(!isDigit(c)) return false;	
	}
	return true; 	// All characters are valid
}

function isIntDec(s)
{
	var i;
	for(i=0; i < s.length; i++)
	{
		var c = s.charAt(i);
		if(!isDigit(c) && c!="." && c!="-") return false;	
	}
	return true; 	// All characters are numbers
}

//==================================
//Get checked radio button value   =
//==================================
function getRadioValue(radioObj)
{
  for (var i=0; i<radioObj.length; i++)
    {
      if (radioObj[i].checked)
         {
           value = radioObj[i].value;
           break;
         }
      }
   return value;
}