從表中刪除最後一行時顯示警報窗口

Question

我有一張表，我在其中動態添加和刪除行。這是我寫的代碼

<SCRIPT TYPE="text/javascript"> 
var count = "2"; 
function addRow(in_tbl_name) 
{ 
var tbody = document.getElementById(in_tbl_name).getElementsByTagName("TBODY")[0]; 
// create row 
var row = document.createElement("TR"); 
// create first col 
var td1 = document.createElement("TD") 
var strHtml1 = "This is the line number " + count; 
td1.innerHTML = strHtml1.replace(/!count!/g,count); 
// create second col 
var td2 = document.createElement("TD") 
var strHtml2 = "<INPUT TYPE='Button' CLASS='Button' onClick='delRow()' VALUE='Delete Row'>"; 
td2.innerHTML = strHtml2.replace(/!count!/g,count); 

// append data to row 
row.appendChild(td1); 
row.appendChild(td2); 
// add to count variable 
count = parseInt(count) + 1; 
// append row to table 
tbody.appendChild(row); 
} 

function delRow() 
{ 
var current = window.event.srcElement; 
//here we will delete the line 
while ((current = current.parentElement) && current.tagName !="TR"); 
    current.parentElement.removeChild(current); 
} 
</SCRIPT> 

這裏是HTML元素的代碼。

<div id="container"> 
<INPUT TYPE="Button" onClick="addRow('tblPets')" VALUE="Add Row"> 

<TABLE ID="tblPets" border="1" STYLE="border width:1 orange dashed;background color:#F0E68C;table-row width:2;"> 

    <TR><TD>Frist col</TD><TD>Second col</TD></TR> 
    <TR><TD>This is the line number 1.</TD><TD><INPUT TYPE="Button" CLASS="Button" onClick="delRow()" VALUE="Delete Row"></TD></TR> 

</TABLE> 
</div> 

到目前爲止一切工作正常。我想不出如何完成的最後一步是，當我從表格中刪除每一行時，將出現一條警告消息，說明alert("Table is empty");。

我怎麼能這樣做？如何讓我的delRow()函數了解表何時完全清空？

任何幫助將不勝感激。

Answer 1

你可以試試這個

if(document.getElementById("myTable").rows.length == 1) 
    alert("this is last row ") 
else if (document.getElementById("myTable").rows.length == 0) 
    alert("table is empty now ") 

Answer 2

實際上，這是我的一個愚蠢的問題..我只是用我的計數變量它確實..

這個如果單純

if (count == 1) 
    alert("Table is empty");