<textareaname="ta1"rows=5cols=50>
aaaaaaaaaaaaaa

cccccccccc
dddddddddddd
fffffffffffff
</textarea>
<inputvalue="1"name="line">
<inputtype=buttononclick="goL(parseInt(line.value));"value="go">
<script>
functiongoL(Line)
{
ta1.focus();
varv=ta1.value.split('\n');
ch=0;
for(vari=0;i<Line-1;i++)
ch+=v[i].length;
varo=ta1.createTextRange();
o.move("character",ch);
o.select();
}
</script>
aaaaaaaaaaaaaa bbbbbbbbbbbbbb cccccccccc dddddddddddd fffffffffffff [Ctrl+A 全选 注:引入外部Js需再刷新一下页面才能执行]