function SetActiveTab(tab_image)
{
	HideAllMainContentBlocks();
	
	var tab_image_id = tab_image.id;
	if(tab_image_id == 'journal_track_your_food')
	{
        	document.getElementById('display_block_journal_track_your_food').style.display = "block";
        	main_image_table.src='../images/large_track_your_food_lose_weight.jpg';
	}
	else if(tab_image_id == 'journal_mini_pen')
	{
        	document.getElementById('display_block_journal_mini_pen').style.display = "block";
        	main_image_table.src='../images/large_pen.jpg';
	}
	else if(tab_image_id == 'journal_fits_in_your_wallet')
	{
        	document.getElementById('display_block_journal_fits_in_your_wallet').style.display = "block";
        	main_image_table.src='../images/large_fits_in_your_wallet_food.jpg';
	}
}

function HideAllMainContentBlocks()
{
        document.getElementById('display_block_journal_track_your_food').style.display 	= "none";
        document.getElementById('display_block_journal_mini_pen').style.display 		= "none";
        document.getElementById('display_block_journal_fits_in_your_wallet').style.display 	= "none";
}

/**************/

function calculate (){
	if (document.myform.weight.value > 0){
		
	}else{
		alert ('Please enter your weight in pounds');
		document.myform.weight.select();
		end();
	}
	
	if (document.myform.height1.value > 0){
		
	}else{
		alert ('Please enter your height');
		document.myform.height1.select();
		end();
	}
	
	if (document.myform.age.value > 0){
		}else{
		alert ('Please enter your age in years');
		document.myform.age.select();
		end();
	}
	
	if (document.myform.height2.value > 0){
		}else{
		document.myform.height2.value=0;
	}
	
	var height0 = (document.myform.height1.value*12) + eval(document.myform.height2.value);
	
	if (document.myform.gender[0].checked == true){
		var calcbmr=66+(6.23*document.myform.weight.value)+(12.78*height0)-(6.8*document.myform.age.value);
		calcbmr /= 10;
		calcbmr = Math.round(calcbmr);
		calcbmr *= 10;
		document.myform.bmr.value=calcbmr;
		for (i=0;i<document.myform.activity.length; i++){
			if (document.myform.activity[i].checked == true){
			actmod = document.myform.activity[i].value; }
			}
		var calctdee=calcbmr*actmod;
		calctdee /= 10;
		calctdee = Math.round(calctdee);
		calctdee *= 10;
		document.myform.tdee.value=calctdee;
		var testgoal=calctdee-500;
		if (testgoal < 1500){
			document.myform.goal.value=1500;
		}else{
			document.myform.goal.value=testgoal;
		}
	}
	else{
		var calcbmr=655+(4.35*document.myform.weight.value)+(4.7*height0)-(4.7*document.myform.age.value);
		calcbmr /= 10;
		calcbmr = Math.round(calcbmr);
		calcbmr *= 10;
		document.myform.bmr.value=calcbmr;
		for (i=0;i<document.myform.activity.length; i++){
			if (document.myform.activity[i].checked == true){
			actmod = document.myform.activity[i].value; }
			}
		var calctdee=calcbmr*actmod;
		calctdee /= 10;
		calctdee = Math.round(calctdee);
		calctdee *= 10;
		document.myform.tdee.value=calctdee;
		var testgoal=calctdee-500;
		if (testgoal < 1200){
			document.myform.goal.value=1200;
		}else{
			document.myform.goal.value=testgoal;
		}
	}
}