JavaScript实现按钮背景色渐变动画

<HTML><HEAD><TITLE>按钮慢慢变色</TITLE>
<STYLE type=text/css>
BODY {
 MARGIN-TOP: 0px; FONT-SIZE: 9pt; MARGIN-LEFT: 0px; MARGIN-RIGHT: 0px; FONT-FAMILY: "宋体"
}
A {
 FONT-WEIGHT: 400; FONT-SIZE: 9pt; COLOR: black; TEXT-DECORATION: none
}
A:hover {
 FONT-WEIGHT: 400; FONT-SIZE: 9pt; COLOR: red; TEXT-DECORATION: underline
}
A:active {
 FONT: 9pt "宋体"; CURSOR: hand; COLOR: #ff0033
}
.STYLE1 {
 color: #000099;
 font-weight: bold;
 font-family: "华文新魏";
 font-size: 30px;
}
.STYLE2 {
 color: #FF3399;
 font-size: 40px;
 font-family: "华文行楷";
}
</STYLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
</HEAD>
<BODY bgColor=#fef4d9>
<CENTER>
 <span class="STYLE2">按钮慢慢变色</span>
</CENTER><BR>
<CENTER>
<TABLE borderColor=#66FF00 border=5 borderlight="green">
 <TBODY>
 <TR>
 <TD align=middle><span class="STYLE1">效果显示</span></TD>
 </TR>
 <TR>
 <TD align=middle>
  <SCRIPT language=JavaScript>
hexColor = ["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"];
function mOver() {
for (i = 0; i < 13; i++) {
setTimeout('document.myForm.button.style.background = "#'+hexColor[12-i]+'0'+hexColor[12-i]+'0c0";', i * 40);
 }
}
function mOut() {
document.myForm.button.value = "进入本站";
for (i = 0; i < 12; i++) {
setTimeout('document.myForm.button.style.background = "#'+hexColor[i]+'0'+hexColor[i]+'0c0";', i * 40);
 }
}
// End -->
</SCRIPT>
  <FORM name=myForm>
  <input onMouseDown='document.myForm.button.value=" 谢谢"' onMouseOver=mOver() onClick='window.location="https://www.jb51.net/"' onMouseOut=mOut() type=button value=鼠标放在上面 name=button >
  </FORM></TD></TR></TBODY></TABLE>
</CENTER>
</BODY>
</HTML>