这个东西是在线写 js 脚本的时候，用来即时查错的东西！也就是，当发现所编写的脚本有问题的时候会有相应的提示，并且在源代码框中高亮标示出错行，方便除错！
运行代码框<HTML><HEAD><TITLE>Debug Textarea</TITLE><meta http-equiv='Content-Type' content='text/html; charset=gb2312'></HEAD><style>* {font-size: 12px}body {margin: 10px; padding: 0px}table.list{cursor: default;border:1px solid #ccccccbackground-color: #cccccc;border-collapse: collapse;border-Color: #cccccc;}</style><script language="javascript">// Coded by windy_sk <windy_sk@126.com> 20040205function reportError(msg,url,line) {var str = "You have found an error as below: \n\n";str += "Err: " + msg + " on line: " + line;alert(str);return true;}window.onerror = reportError;document.onkeydown = function() {if(event.ctrlKey){switch(event.keyCode) {case 82: //rruncode();break;case 83: //ssavecode();break;case 71: //ggoto(prompt('Please input the line number', '1'));break;case 65: //adocument.execCommand("SelectAll");break;case 67: //cdocument.execCommand("Copy");break;case 88: //xdocument.execCommand("Cut");break;case 86: //vdocument.execCommand("Paste");break;case 90: //zdocument.execCommand("Undo");break;case 89: //ydocument.execCommand("Redo");break;default:break;}event.keyCode = 0;event.returnValue = false;}return;}function show_ln(){var txt_ln = document.getElementById('txt_ln');var txt_main = document.getElementById('txt_main');txt_ln.scrollTop = txt_main.scrollTop;while(txt_ln.scrollTop != txt_main.scrollTop) {txt_ln.value += (i++) + '\n';txt_ln.scrollTop = txt_main.scrollTop;}return;}function editTab(){var code, sel, tmp, r;event.returnValue = false;sel =event.srcElement.document.selection.createRange();r = event.srcElement.createTextRange();switch (event.keyCode){case (8):if (!(sel.getClientRects().length > 1)){event.returnValue = true;return;}code = sel.text;tmp = sel.duplicate();tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top);if(sel.parentElement() != tmp.parentElement()) return;;sel.setEndPoint('startToStart', tmp);sel.text = sel.text.replace(/^\t/gm, '');code = code.replace(/^\t/gm, '').replace(/\r\n/g, '\r');r.findText(code);r.select();break;case (9):if (sel.getClientRects().length > 1){code = sel.text;tmp = sel.duplicate();tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top);if(sel.parentElement() != tmp.parentElement()) return;sel.setEndPoint('startToStart', tmp);sel.text = '\t'+sel.text.replace(/\r\n/g, '\r\t');code = code.replace(/\r\n/g, '\r\t');r.findText(code);r.select();}else{sel.text = '\t';sel.select();}breakcase (13):tmp = sel.duplicate();tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top);if(sel.parentElement() != tmp.parentElement()) return;tmp.setEndPoint('endToEnd', sel);sel.text = '\r\n' + tmp.text.replace(tmp.text.replace(/^[\t ]+/g, ""),"");sel.select();break;default:event.returnValue = true;break;}return;}function runcode() {var str = document.getElementById("txt_main").value;var code_win = window.open('about:blank');code_win.document.open();code_win.document.writeln("<script>");code_win.document.writeln("function reportError(msg,url,line){\nline-=14;\nvar str='You have found an error as below: \\n\\n';\nstr+='Err: '+msg+' on line: '+(line);\nalert(str);\nopener.goto(line);\nopener.focus();\nwindow.onerror=null;\nsetTimeout('self.close()',10);\nreturn true;\n}");code_win.document.writeln("window.onerror = reportError;");code_win.document.writeln("<\/script>");code_win.document.writeln(str);code_win.document.close();return;}function savecode() {var str = document.getElementById("txt_main").value;var code_win = window.open('about:blank','_blank','top=10000');code_win.document.open();code_win.document.writeln(str);code_win.document.close();code_win.document.execCommand('saveas','','code.html');code_win.close();return;}function goto(ln) {if(!/^\d+$/.test(ln) || ln==0) return;var obj = document.getElementById("txt_main");var rng = obj.createTextRange();var arr = obj.value.split(/\n/);if(ln>arr.length) ln = arr.length;var str_tmp = "";for(var i=0; i<ln-1; i++) {str_tmp += arr[i];}rng.moveStart('character',str_tmp.length);str_tmp = "";for(i=ln; i<arr.length; i++) {str_tmp += arr[i];}rng.moveEnd('character',-str_tmp.length); rng.select();return;}window.onload = function() {document.getElementById("txt_main").value = "<script>\nalert(')\n<\/script>";}</script><BODY><table width='600' class='list' border='1' bgcolor='#eeeeee' bordercolorlight='#000000' bordercolordark='#FFFFFF' cellpadding='0' cellspacing='0'> <tr bgcolor='#cccccc'> <td colspan='2' height='20' align='center'><b>Debug Textarea</b></td> </tr> <tr> <td colspan='2'> <table width='95%' border='0' align='center' > <tr> <td align='center'><br /> <textarea id='txt_ln' name='content' rows='10' style='width:40px;overflow:hidden;height:200px;border-right:0px;text-align:right;line-height:14px' onselectstart='this.nextSibling.focus();return false' readonly></textarea><textarea id='txt_main' name='content' rows='10' cols='80' onkeydown='editTab()' onkeyup='show_ln()' onscroll='show_ln()' wrap='off' style='overflow:auto;height:200px;padding-left:5px;border-left:0px;line-height:14px'></textarea> <script>for(var i=1; i<=20; i++) document.getElementById('txt_ln').value += i + '\n';</script> </td> </tr> <tr> <td align='center'><br /> <input type='button' value=' 运 行 ' onclick='runcode()' accesskey='r'> <input type='button' value=' 保 存 ' onclick='savecode()' accesskey='s'> <input type='button' value=' 跳 转 ' onclick="goto(prompt('Please input the line number', '1'))" accesskey='g'> </td> </tr> </table> </td> </tr></table></BODY></HTML>