function isUnsignedInteger()
{
var check = true;

var check_feet = document.forms.bmi_calculator.feet.value;
var check_inches = document.forms.bmi_calculator.inches.value;
var check_weight = document.forms.bmi_calculator.weight.value;


var reg_exp = /^[0-9]+$/ ;

if (check_feet == "" && check_weight == "")
 {
  alert("Please enter your height and weight.");
  check = false;
 }

else if (check_feet == "")
 {
 alert("Please enter " + document.getElementById('feet_meters').value + " as a number.");
 check = false;
 }

else if (!reg_exp.test(check_feet))
 {
 alert("Please enter " + document.getElementById('feet_meters').value + " as a number.");
 check = false;
 }
else if (!reg_exp.test(check_inches) && check_inches != "")
 {
 alert("Please enter " + document.getElementById('inches_cm').value + " as a number.");
 check = false;
 }
else if (!reg_exp.test(check_weight))
 {
 alert("Please enter " + document.getElementById('lbs_kg').value + " as a number.");
 check = false;
 }

return check;
}

function isUnsignedInteger2()
 {
  var check = true;
  
  var check_waist = document.forms.waist_hips_calculator.waist.value;
  var check_hips = document.forms.waist_hips_calculator.hips.value; 
  
  var reg_exp = /^[0-9]+$/ ;
  
  if (check_waist == "" && check_hips == "")
   {
	 alert("Please enter your waist and hips measurements.");
	 check = false;
   }
   else if (check_waist == "" || check_hips == "")
    {
	  alert("Please enter both your waist and hips measurements.");
	  check = false;
	}
   else if (!reg_exp.test(check_waist))
	{
	 alert("Please enter " + document.getElementById('waist_size').value + " as a number.");
	 check = false;
	}
	else if (!reg_exp.test(check_hips))
	{
	 alert("Please enter " + document.getElementById('hips_size').value + " as a number.");
	 check = false;
	}
return check;
  
 } // function


function metric_units1()
 {

var feet_or_meters = document.getElementById('feet_meters') ;
var inches_or_cm = document.getElementById('inches_cm') ;
var lbs_or_kg = document.getElementById('lbs_kg') ;

if (feet_or_meters.value == 'feet')
 {
  inches_or_cm.value = 'inches';
  lbs_or_kg.value = 'pounds';
  if (document.getElementById('inches_input').value > 11)
    {
    document.getElementById('inches_input').value = "";
    document.getElementById('inches_input').focus();
	}
 }
else if (feet_or_meters.value == 'meters')
{
  inches_or_cm.value = 'centimeters';
  lbs_or_kg.value = 'kg';
 }
	 
 } // function
 
 
function metric_units2()
 {

var feet_or_meters = document.getElementById('feet_meters') ;
var inches_or_cm = document.getElementById('inches_cm') ;
var lbs_or_kg = document.getElementById('lbs_kg') ;

if (inches_or_cm.value == 'inches')
  {
  feet_or_meters.value = 'feet';
  lbs_or_kg.value = 'pounds';
  if (document.getElementById('inches_input').value > 11)
    {
    document.getElementById('inches_input').value = "";
    document.getElementById('inches_input').focus();
	}
  }
 else if (inches_or_cm.value == 'centimeters')
  {
  feet_or_meters.value = 'meters';
  lbs_or_kg.value = 'kg';
  }
	 
 } // function
 
function metric_units3()
 {

var feet_or_meters = document.getElementById('feet_meters') ;
var inches_or_cm = document.getElementById('inches_cm') ;
var lbs_or_kg = document.getElementById('lbs_kg') ;

if (lbs_or_kg.value == 'pounds')
 {
  feet_or_meters.value = 'feet';
  inches_or_cm.value = 'inches';
  if (document.getElementById('inches_input').value > 11)
    {
    document.getElementById('inches_input').value = "";
    document.getElementById('inches_input').focus();
	}
 }
else if (lbs_or_kg.value == 'kg')
 {
  feet_or_meters.value = 'meters';
  inches_or_cm.value = 'centimeters';
 }
	 
 } // function
 
function metric_units4()
 {

var waist_units = document.getElementById('waist_size') ;
var hips_units = document.getElementById('hips_size') ;
var waist_input = document.getElementById("waist_input")
var hips_input = document.getElementById("hips_input")

if (waist_units.value == 'inches')
  hips_units.value = 'inches';
else if (waist_units.value == 'centimeters')
  hips_units.value = 'centimeters';

waist_input.value = "";
hips_input.value = "";
  
	 
 } // function
 
function metric_units5()
 {

var waist_units = document.getElementById('waist_size') ;
var hips_units = document.getElementById('hips_size') ;
var waist_input = document.getElementById("waist_input")
var hips_input = document.getElementById("hips_input")

if (hips_units.value == 'inches')
  waist_units.value = 'inches';
else if (hips_units.value == 'centimeters')
  waist_units.value = 'centimeters';
  
waist_input.value = "";
hips_input.value = "";
	 
 } // function

function max_length()
 {
  var waist_units = document.getElementById('waist_size') ;
  var hips_units = document.getElementById('hips_size') ;
 
  if (waist_units.value == 'centimeters')
   {
	 document.getElementById("waist_input").maxLength = 3;
	 document.getElementById("hips_input").maxLength = 3;
   }
   else
    {
	 document.getElementById("waist_input").maxLength = 2;
	 document.getElementById("hips_input").maxLength = 2;
   }
 } // function
 
 function eleven_inches()
  {
   var check_inches = document.getElementById('inches_input');
   if (document.getElementById('inches_cm').value == 'inches' && check_inches.value > 11)
   {
   alert("Maximum number of inches is 11.");
   check_inches.value = "";
   check_inches.focus();
   }
  }  // function