echo "<link rel=\"stylesheet\" type=\"text/css\" href=\"images/style.css\">";
echo "<input class=\"forumbuttons\" type=\"submit\" size=\"10\" id=\"edit1\" name=\"submit[edit1]\" value=\"Edit1\">&nbsp;";
echo "<input class=\"forumbuttons\" type=\"submit\" size=\"10\" id=\"edit2\" onmouseover=\"alert('123');\" name=\"edit2\" value=\"Edit2\">&nbsp;";

and the css has 2 lines for that:

INPUT.forumbuttons {text-align:center; BORDER-RIGHT:#999999 1px solid; BORDER-TOP:#999999 1px solid; BORDER-LEFT:#999999 1px solid; BORDER-BOTTOM:#000000 2px solid; BACKGROUND-COLOR:#6D7095; COLOR:#FFF;}

INPUT.forumbuttons {BACKGROUND-COLOR: #5D6080; COLOR: #FFF;}