how to disable a toolbar after it is ued in fckeditor.

hi ,

I am working for a drupal site.. i have one issue with the fckeditor


when i select a text and click bold it is changing to bold..

when i click on the science term plugin it is changing from bold to plaintext

again when i m clicking the science term plugin second time it is not changing from plaintext to bold.


can u pls help m e in my issue...




if(selection.length > 0)
{

FCK.InsertHtml('<span class="science-term">' + selection + '</span>');

// in the above step it is changing from bold to plaintext

when i click on the plugin again it is not restoring to bold..


pls help me in this ..

THanks,

Mkhm