如何用javascript设置图片的边框颜色？？？？？？

<script type="text/javascript">

function imgborder(){

//页面中第n个图片的边框

document.getElementsByTagName('img')[n].style.border="1px red solid"

//指定id图片的边框

//document.getElementById('aa').style.border="1px red solid"

//某元素下第n个图片的边框

//document.getElementById('bb').getElementsByTagName('img')[n].style.border="1px red solid"

}

window.onload=imgborder</script>

以下是改变文本框字体的颜色!<br><input name="test" type="text" id="test" value="点击按钮看我变化"><br><input name="a" type="button" id="a" tvalue="black" value="黑色" onclick="document.getelementbyid('test').style.color=document.getelementbyid('test').tvalue=this.tvalue"><br><input name="b" type="button" id="b" tvalue="red" value="红色" onclick="document.getelementbyid('test').style.color=document.getelementbyid('test').tvalue=this.tvalue"><br><input name="c" type="button" id="d" tvalue="green" value="绿色" onclick="document.getelementbyid('test').style.color=document.getelementbyid('test').tvalue=this.tvalue"><br><input name="e" type="button" id="e" tvalue="green" value="获取文本框颜色属性值" onclick="alert(!document.getelementbyid('test').tvalue?null:document.getelementbyid('test').tvalue)"><br><br>如果是要改变文本框背景色的话就用以下的!<br><input name="test" type="text" id="test" value="点击按钮看我变化"><br><input name="a" type="button" id="a" tvalue="black" value="黑色" onclick="document.getelementbyid('test').style.background=document.getelementbyid('test').tvalue=this.tvalue"><br><input name="b" type="button" id="b" tvalue="red" value="红色" onclick="document.getelementbyid('test').style.background=document.getelementbyid('test').tvalue=this.tvalue"><br><input name="c" type="button" id="d" tvalue="green" value="绿色" onclick="document.getelementbyid('test').style.background=document.getelementbyid('test').tvalue=this.tvalue"><br><input name="e" type="button" id="e" tvalue="green" value="获取文本框颜色属性值" onclick="alert(!document.getelementbyid('test').tvalue?null:document.getelementbyid('test').tvalue)">

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