I was able to get help from a coworkers son on how to get my code to work (there's no way I would have ever figured it out myself!)...

Here it is...

[HTML]
<SCRIPT LANGUAGE="JavaScript">
function calculate()
{
var g = 0;
var f = 0;
var c = 0;
if (document.getElementById("g").checked) { g = 1 };
if (document.getElementById("f").checked) { f = 3 };
if (document.getElementById("c").checked) { c = 5 };
var s = g + f + c;
var ans = "Problem";
if ( s == 0) { ans = "Hey!, you need to select at least two categories."};
if ( s == 1) { ans = "Hey!, you need to also select either fast or cheap."};
if ( s == 3) { ans = "Hey!, you need to also select either good or cheap."};
if ( s == 4) { ans = "The work product will be good and fast, but it won't be cheap!"};
if ( s == 5) { ans = "Hey!, you need to also select either fast or good."};
if ( s == 6) { ans = "The work product will be good and cheap, but it won't be fast!"};
if ( s == 8) { ans = "The work product will be fast and cheap, but it won't be good!"};
if ( s == 9) { ans = "Come on! You can't have a work product that is all three!"};
document.getElementById("ans").value=ans;
}
</SCRIPT>
<TABLE>
<TR>
<TD><BIG><B>Check two of the three options below and then click the "Process" button.</B></BIG>
<hr no shade size="2">
</TD></TR>
<TR>
<TD align="left" valign="top">
<INPUT TYPE="checkbox" ID="g"> Good (i.e., accurate/correct/etc.)<br>
<INPUT TYPE="checkbox" ID="f"> Fast (i.e., on/ahead of schedule)<br>
<INPUT TYPE="checkbox" ID="c"> Cheap (i.e., on/under budget)</TD>
</TR>
<TR>
<TD>
&nbsp;
</TD>
</TR>
<TR>
<TD align="center" valign="top">
<INPUT TYPE=button VALUE="Process" onClick="calculate()">
</TD>
</TR>
<TR>
<TD align="center">
<INPUT TYPE="text" ID="ans" SIZE="75"><br>
</TD>
</TR>
</TABLE>[/HTML]