// Java Document

//-- clearing and replacing text in the form input fields --//
function clearText(thefield) {
  if (thefield.defaultValue==thefield.value) { thefield.value = "" }
} 
function replaceText(thefield) {
  if (thefield.value=="") { thefield.value = thefield.defaultValue }
}


//-- BAC --//

function computeIt(form) { 
 
var lbs = form.weight.options[form.weight.selectedIndex].value; 
var numLbs = new Number(lbs); 
 
var drinks = form.drinks.options[form.drinks.selectedIndex].value; 
var numDrinks = new Number(drinks); 
 
var alco = numDrinks*.045; 
var alcohol = new Number(alco); 
 
var hours = form.time.options[form.time.selectedIndex].value; 
var numHours = new Number(hours); 
 
var metabol = numHours*.012; 
var metabolism = new Number(metabol); 


if (form.gender.options[form.gender.selectedIndex].value == "male") { 
        gendervalue = ".58"; 
        } else { 
                gendervalue = ".49"; 
                }
                 
       if (form.drinks.options[form.drinks.selectedIndex].value == "null")
      { 
       
       form.average.value = " ";
       alert("Please select number of drinks")
       
      }
	   
	  if (form.time.options[form.time.selectedIndex].value == "null")
      { 
       form.average.value = " ";
       alert("Please enter number of hours")
       
      } 
	   
	  if (form.gender.options[form.gender.selectedIndex].value == "null")
      { 
       
       form.average.value = " ";
       gendervalue = null;
       alert("Please enter gender")
       
      }
	  
	  if (form.weight.options[form.weight.selectedIndex].value == "null") 
      { 
       form.average.value = " ";
       alert("Please select a weight")
      
      }  
      
                
                
var numSex = new Number(gendervalue); 
 
 
var weight = numLbs/2.2046; 
var lbs = new Number(weight); 
 
var water = lbs*numSex; 
var bodywater = new Number(water); 
 
var millwater = bodywater*1000; 
var milliliters = new Number(millwater); 
 
var oz = 23.36/milliliters; 
var ounces = new Number(oz); 
 
var gram = ounces*.806; 
var grams = new Number(gram); 
 
var gramsmill = grams*100; 
var bac0 = new Number(gramsmill); 
 
var bac1 = bac0*alcohol; 
var bac2 = new Number(bac1); 
 
var bac3 = bac2-metabolism; 
if (bac3 < 0) { 
        var result = "0.000"; 
} 
var bac4 = bac3 + ""; 
var result = bac4.substring(0,5); 


//-- code for BAC results --//
if (result >= 0.08){
	 form.average.value = result; 
	 document.getElementById('average').style.color = 'red'
	}
	
	else { form.average.value = result;  
	 document.getElementById('average').style.color = 'black'
	}


if (result <= 0)

	{
		form.average.value = result;
		document.getElementById('average').value = "Negligible amount"
	}
	 

if (result == "NaN")
	{
		form.average.value = result;
		document.getElementById('average').style.color = 'white'
	}


if (result == "Infin")
	{
		form.average.value = result;
		document.getElementById('average').style.color = 'white'
	}



}
// -- end BAC --//