用 javascript 限制上傳檔案類型

// ========== JavaScript ==========

function doc_preview(x) 

{

var ext = x.value;

var ext_length = ext.lastIndexOf('.');

ext = ext.substring(ext_length+1,ext.length);  // get file type

ext = ext.toLowerCase();

if(ext != 'txt' && ext != 'doc' && ext != 'pdf' && ext != 'xls')

{

document.getElementById(x.id).value="";  // for FF

document.getElementById(x.id).outerHTML = '<input type="file" name="' + x.id + '" id="' + x.id + '" onChange="doc_preview(this)" />'; // for IE & Other

alert("<{$T_no_rule}>");

}

if(!x || !x.value) return;  

}

//========== HTML ==========


<input type="file" name="tea_crs_file" id="tea_crs_file" onChange="doc_preview(this)" />

記得上傳檔案的 <form/> 要加上 <form enctype="multipart/form-data"/> .