首先引用文件

<script src="jquery.min.js"></script>
<script src="libs/modernizr.js"></script>
<script src="libs/jSignature.min.noconflict.js"></script>

这是一款手写签名jSignature插件，可以提取签名数据，

$(document).ready(function() {
	
	// This is the part where jSignature is initialized.
	var $sigdiv = $("#signature").jSignature({'UndoButton':true})
	
	// All the code below is just code driving the demo. 
	, $tools = $('#tools')
	, $extraarea = $('#displayarea')
	, pubsubprefix = 'jSignature.demo.'
	
	var export_plugins = $sigdiv.jSignature('listPlugins','export')
	, chops = ['<span><b>提取签名数据: </b></span><select>','<option value="">(select export format)</option>']
	, name
	for(var i in export_plugins){
		if (export_plugins.hasOwnProperty(i)){
			name = export_plugins[i]
			chops.push('<option value="' + name + '">' + name + '</option>')
		}
	}
	chops.push('</select><span><b> or: </b></span>')
	
	$(chops.join('')).bind('change', function(e){
		if (e.target.value !== ''){
			var data = $sigdiv.jSignature('getData', e.target.value)
			$.publish(pubsubprefix + 'formatchanged')
			if (typeof data === 'string'){
				$('textarea', $tools).val(data)
			} else if($.isArray(data) && data.length === 2){
				$('textarea', $tools).val(data.join(','))
				$.publish(pubsubprefix + data[0], data);
			} else {
				try {
					$('textarea', $tools).val(JSON.stringify(data))
				} catch (ex) {
					$('textarea', $tools).val('Not sure how to stringify this, likely binary, format.')
				}
			}
		}
	}).appendTo($tools)