function merge(tableId, col) {
	var tr = document.getElementById(tableId);
	for (var i=1; i<tr.rows.length; i++) {                //表示数据内容的第二行
	    if (tr.rows[i].cells[col].innerHTML == tr.rows[i - 1].cells[col].innerHTML) {//col代表列
		t = i-1;
		while(tr.rows[i].cells[col].innerHTML == tr.rows[t].cells[col].innerHTML) {
		    tr.rows[i].cells[col].style.display="none";
		    if (tr.rows[t].cells[col].rowSpan <= (i-t)) {  
			tr.rows[t].cells[col].rowSpan +=1;      //设置前一行的rowspan+1
		    }
		    i++;
		}
	    }               
	}
}