Hello,

I'm new here and I hope I'm in the correct category...

First, sorry for my bad english, I'm from switzerland.

I need help with JavaScript. I have copied this calculator but I can't change it.

HTML Code:
<script language ="JavaScript">
<!--
	function calculate_finance() {

		amount = document.getElementById('calc_amount').value.replace(',','.');
		amount = amount.replace(/[^0-9\.]/g, '');
		
				
		
							if (amount <= 99.99)		{var period = 30; var interest = 2.4; var deviation_percent = 2.4; }
						
	
							else if (amount >= 100.00 && amount <= 999.99)	{var period = 60; var interest = 2.8; var deviation_percent = 2.8; }
							
		
							else if (amount >= 1000.00 && amount <= 3000.00)	{var period = 90; var interest = 3.4; var deviation_percent = 3.4; }
						
	
				
		
		compound = parseInt(document.getElementById('calc_compounding').value);
		if (compound > 100) compound = 100;
		else if ((compound < 0) || (isNaN(compound))) compound = 0;
		
		document.getElementById('calc_compounding').value = compound;
		
		var profit = this_profit = direct = this_direct = first_profit = last_profit = total_profit = deviation = 0;
		for (i=0; i < period; i++) {
			profit =  Math.round((amount*1 + this_profit*1) * interest)/100;
			direct =  Math.round(profit*(1-compound*0.01)*100)/100;
			if (first_profit == 0) first_profit = profit;
			last_profit = profit;
			profit -= direct;
			this_profit += profit*1;
			this_direct += direct*1;
		}
		
		total_profit = Math.round((this_profit*1 + this_direct*1)*10)/10;			
		total_profit = isNaN(total_profit)?0:total_profit;
		
		daily_profit = Math.round(total_profit*10/period)/10;				
		
		total_return = Math.round(total_profit*10+amount*10)/10;

		if (total_return < 1000) {
			total_return = Math.round(total_profit*10+amount*10)/10;
			deviation = Math.round(total_return*deviation_percent*0.5*10/100)/10;
		}
		else {
			total_return = Math.round(total_profit*1+amount*1);
			deviation = Math.round(total_return*deviation_percent*0.5/100);
		}

		deviation = deviation<0.1?0.1:deviation;
		
		roi_min = Math.round((total_return-deviation)*1000/amount)/10;
		roi_max = Math.round((total_return+deviation)*1000/amount)/10;
		roi = isNaN(roi_max)?0:roi_min+' <small>%</small> - '+roi_max;		
		
		document.getElementById('calc_total_return').innerHTML = '<b>'+total_return+'</b> $';
		document.getElementById('calc_roi').innerHTML = '<b>'+roi+'</b> %';
		document.getElementById('calc_period').innerHTML = '<b>'+period+'</b> '+ (period<100?'business ':'b/') + 'days';
		//document.getElementById('calc_end_date').innerHTML = '<b>'+end_date+'</b>';
		document.getElementById('calc_amount').value = amount;
		if (deviation>0) document.getElementById('calc_deviation').innerHTML = '<b>'+deviation+'</b> $';
		else document.getElementById('calc_deviation').innerHTML = '';

	}

	function save_calc_data() {	
		amount = document.getElementById('calc_amount').value.replace(',','.');
		amount = amount.replace(/[^0-9\.]/g, '');
		if (amount < 5) {
			amount = 5;
			document.getElementById('calc_amount').value = amount; 
		}
		document.cookie="calc_amount="+amount+"; path=/; expires=Mon, 01-Jan-2018 00:00:00 GMT";
		document.cookie="calc_compounding="+document.getElementById('calc_compounding').value +"; path=/; expires=Mon, 01-Jan-2018 00:00:00 GMT";
		calculate_finance();
	}
-->
</script>

<div id="bottom-container-3" class="container-col-33">
	<div class="padding-10">			
			<img class="left ml-10" src="/img/bottom-container-calculator.png" height="38" width="42" alt="Financial calculator">
			<h3>Financial Calculator</h3>
			
			<div class="h-20"></div>

			<div class="financial-calc">
			<table>
				<tr>
					<td width=82><label>Investment<br >amount</label></td>
					<td width=55><input type="text" id="calc_amount" onblur="calculate_finance();" onkeyup="javascript:this.value=this.value.replace(/[^0-9\.\,]/g, ''); calculate_finance();" onchange="save_calc_data();" value="100"></td>					
					<td width=10>&nbsp;</td>
					<td width=70><label>Total<br />return</label></td>

					<td class="data"><span id="calc_total_return"><b>118</b> $</span> <span id="calc_deviation"><b>2.4</b> $</span></td>
				</tr>
				<tr>
					<td><label>Compounding</label></td><td><input type="text" id="calc_compounding" onblur="calculate_finance();" onkeyup="javascript:this.value=this.value.replace(/[^0-9\.\,]/g, ''); calculate_finance();" onchange="save_calc_data();" value=""></td>
					<td>&nbsp;</td>
					<td><label>Period</label></td><td class="data"><span id="calc_period"><b>10</b> calendar days</span></td>
				</tr>
				<tr>
					<td colspan=2>&nbsp;<!--<label>End date</label></td><td class="data"><span id="calc_end_date"><b></b></span>--></td>
					<td>&nbsp;</td>
					<td><label>ROI</label></td><td class="data"><span id="calc_roi"><b>160</b> %</span></td>
				</tr>
			</table>
			<script language ="JavaScript">calculate_finance();</script>
		</div>
	</div>
</div></div>
I want to add this (red text) but when I add:

Code:
document.getElementById('daily_profit').innerHTML = '<b>'+daily_profit+'</b> $';
and this in the table:

HTML Code:
<tr>
					<td colspan=2>&nbsp;<!--<label>End date</label></td><td class="data"><span id="calc_end_date"><b></b></span>--></td>
					<td>&nbsp;</td>
					<td><label>ROI</label></td><td class="data"><span id="daily_profit"><b>160</b> %</span></td>
				</tr>
it will change the period to 10 days... I can't fix that. Any ideas?