IE6中链接A的href为javascript协议时不在当前页面跳转

<p><a href="javascript:;" onclick="jumpSina()">Sina</a></p>
<p><a href="javascript:void 0;" onclick="jumpSohu()">Sohu</a></p>
<script>
function jumpSina() {
location.href = 'http://www.sina.com.cn'
}
function jumpSohu() {
location.href = 'http://www.sohu.com'
}
</script>

<p><a href="###" onclick="jumpSina()">Sina</a></p>
<p><a href="#none" onclick="jumpSohu()">Sohu</a></p>
<script>
function jumpSina() {
location.href = 'http://www.sina.com.cn'
}
function jumpSohu() {
location.href = 'http://www.sohu.com'
}
</script>

<p><a href="javascript:;" onclick="jumpSina()">Sina</a></p>
<script>
function jumpSina() {
window.open( 'http://www.sina.com.cn')
}
</script>