table表格合并封装的小插件

/**
 * 封装的一个JQuery小插件
 * @param {Object} colNo
 * @memberOf {TypeName} 
 * @return {TypeName} 
 */
jQuery.fn.rowspan = function(colNo) {  
return this.each(function(){ 
var that; 
$('tr', this).each(function(row){
$('td:eq('+ colNo +')', this).filter(':visible').each(function(col){ 
if (that != null && $(this).html() == $(that).html()) {
rowspan = $(that).attr("rowSpan"); 
if (rowspan == undefined) { 
$(that).attr("rowSpan", 1); 
rowspan = $(that).attr("rowSpan"); 
} 
rowspan = Number(rowspan) + 1;
$(that).attr("rowSpan", rowspan); 
$(this).hide(); 
} else { 
that = this; 
} 
}); 
}); 
}); 
};