function AddCustomParams()
AddPanel('Custom');
text = {'customVars.kf = 1000;'};
desc = {'Text area for custom m-code where you can define any additional variables accessible from the expressions in editboxes.', ...
'The variables must be put into the %customVars struct.', ...
'', ...
'<b>Example:</b>', ...
'<pre>customCode: customVars.r = roots([1, -3.1, 0.3]);', ...
' customVars.myVar3 = 0.1;', ...
' n = 1000; % not exposed variable', ...
' customVars.myVar5 = log10(n);</pre>', ...
'<b>Correct referencing:</b>', ...
'<pre>cai0: 1.2 * r(1) * r(2) [mM]', ...
'DCa: 3.4 * r(1) / r(2) [um2/ms]', ...
'TBufs: 5.6 * myVar3 * myVar5 [mM]', ...
'kfs: 7.8 * myVar5 ^ 2 [/mM-ms]</pre>(no "customVars." prefixes are required here)', ...
'', ...
'<b>Incorrect referencing:</b>', ...
'<pre><font color="red">KDs: 9.0 * n [uM]</font></pre>(the variable "n" was not exposed)'};
AddCustomCodeTextArea('customCode', text, 'customVars', desc);
end