Calculators Effects >>> Interest.


		<script 
		language="javascript"
		type="text/javascript">

		/* Visit http://www.yaldex.com/ 
		for full source code

		and get more free JavaScript, CSS and DHTML scripts! */

		<!-- Begin

		function 
		checkNumber(input,
		min,
		max, 
		msg)
		{

		msg 
		= 
		msg +
		" field has invalid data: "
		+
		input.value;

		var 
		str =
		input.value;

		for
		(var 
		i =
		0; 
		i < 
		str.length; 
		i++)
		{

		var
		ch
		= 
		str.substring(i, 
		i +
		1)

		if
		((ch
		<
		"0"
		||
		"9"
		<
		ch)
		&&
		ch
		!=
		'.')
		{

		alert(msg);

		return
		false;

		      
		}

		   
		}

		var 
		num =
		parseFloat(str)

		if
		(num
		<
		min
		||
		max
		< 
		num)
		{

		alert(msg
		+
		" not in range ["
		+
		min
		+
		".."
		+
		max
		+
		"]");

		return
		false;

		   
		}

		input.value
		= 
		str;

		return
		true;

		}

		function 
		computeField(input)
		{

		if
		(input.value
		!=
		null
		&&
		input.value.length
		!=
		0)

		input.value
		=
		""
		+
		eval(input.value);

		computeForm(input.form);

		}

		function 
		computeForm(form)
		{

		if
		((form.payments.value
		==
		null
		||
		form.payments.value.length
		==
		0)
		||

		(form.interest.value
		==
		null
		||
		form.interest.value.length
		==
		0)
		||

		(form.principal.value
		==
		null
		||
		form.principal.value.length
		==
		0))
		{

		return;

		}

		if
		(!checkNumber(form.payments,
		1,
		480,
		"# of payments")
		||

		!checkNumber(form.interest,
		.001,
		99,
		"Interest")
		||

		!checkNumber(form.principal,
		100,
		10000000,
		"Principal"))
		{

		form.payment.value
		=
		"Invalid";

		return;

		}

		var 
		i =
		form.interest.value;

		if
		(i
		>
		1.0)
		{

		i 
		= 
		i /
		100.0;

		form.interest.value
		= 
		i;

		}

		i 
		/=
		12;

		var
		pow
		=
		1;

		for
		(var 
		j =
		0; 
		j <
		form.payments.value; 
		j++)

		pow
		=
		pow
		*
		(1
		+ 
		i);

		money 
		=
		""
		+
		.01*
		Math.round(100*(form.principal.value
		*
		pow
		* 
		i)
		/
		(pow
		-
		1));

		dec 
		= 
		money.indexOf(".");

		dollars 
		= 
		money.substring(0,dec);
		

		cents = 
		money.substring(dec+1,dec+3);

		cents 
		=
		(cents.length
		<
		2)
		? 
		cents +
		"0"
		: 
		cents;

		money 
		= 
		dollars +
		"."
		+ 
		cents;

		form.payment.value
		= 
		money;

		}

		function 
		clearForm(form)
		{

		form.payments.value
		=
		"";

		form.interest.value
		=
		"";

		form.principal.value
		=
		"";

		}

		// done hiding from old browsers 
		-->

		</script>

		<FORM
		method=POST>

		<TABLE
		border>

		<TR>

		<TD>

		<DIV
		ALIGN=CENTER>  
		# of<br>Payments</DIV>

		</TD>

		<TD>

		<DIV
		ALIGN=CENTER>Interest<br>Rate</DIV>

		</TD>

		<TD>

		<DIV
		ALIGN=CENTER>Principal</DIV>

		</TD>

		<TD>

		</TD>

		<TD>

		<DIV
		ALIGN=CENTER> 
		Monthly<br> 
		Payment</DIV>

		</TD>

		</TR>

		<TR>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=payments 
		SIZE=5
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=interest 
		SIZE=6
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=principal
		SIZE=9
		onChange=computeField(this)>
		

		</TD>

		<TD> 

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=payment  
		SIZE=9
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE="button"
		VALUE="Compute"  
		onClick=computeForm(this.form)>
		

		</TD>

		<TD>

		<INPUT
		TYPE="reset" 
		VALUE="Reset"    
		onClick=clearForm(this.form)>
		

		</TD>

		</TR>

		</FORM>

		<FORM 
		method=POST>

		<TR>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=payments 
		SIZE=5
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=interest 
		SIZE=6
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=principal
		SIZE=9
		onChange=computeField(this)>
		

		</TD>

		<TD> 

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=payment  
		SIZE=9
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE="button"
		VALUE="Compute"  
		onClick=computeForm(this.form)>
		

		</TD>

		<TD>

		<INPUT
		TYPE="reset" 
		VALUE="Reset"    
		onClick=clearForm(this.form)>
		

		</TD>

		</TR>

		</FORM>

		<FORM 
		method=POST>

		<TR>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=payments 
		SIZE=5
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=interest 
		SIZE=6
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=principal
		SIZE=9
		onChange=computeField(this)>
		

		</TD>

		<TD>

		</TD>

		<TD>

		<INPUT
		TYPE=TEXT
		NAME=payment  
		SIZE=9
		onChange=computeField(this)>
		

		</TD>

		<TD>

		<INPUT
		TYPE="button"
		VALUE="Compute"  
		onClick=computeForm(this.form)>
		

		</TD>

		<TD>

		<INPUT
		TYPE="reset" 
		VALUE="Reset"    
		onClick=clearForm(this.form)>

		</TD>

		</TR>

		</TABLE>

		</FORM>