Javascript coding help!

[eva21]

I have a select table in HTML...and when you click button up, it moves a text up. When you click down, it moves it down...here is the javascript:

function moveup(){

var selObj = document.getElementById('quest');

var thisline = selObj.selectedIndex;

var lineabove = thisline - 1;

//alert('lineabove = ' + lineabove)

if(thisline == 0)

{

alert('Sorry, you already have reached the top')

}

if(thisline >= 0){

  selObj.value = selObj.options[lineabove].text;

  selText = selObj.options[thisline].text;

  selVal = selObj.options[thisline].value;

  upVal = selObj.options[lineabove].value;

  upText = selObj.options[lineabove].text;

  selObj.options[lineabove].text = selText;

  selObj.options[lineabove].value = selVal;

  selObj.options[thisline].value = upVal;

  selObj.options[thisline].text = upText;

  selObj.selectedIndex = lineabove;

} // end if

} // end of moveup

 

function movedown(){

var selObj = document.getElementById('quest');

var thisline = selObj.selectedIndex;

var lineabove = thisline + 1;

//alert('lineabove = ' + lineabove)

if (thisline > 3){

alert('Im sorry, you have reached the bottom')

}

if(thisline >= 0){

  selObj.value = selObj.options[lineabove].text;

  selText = selObj.options[thisline].text;

  selVal = selObj.options[thisline].value;

  upVal = selObj.options[lineabove].value;

  upText = selObj.options[lineabove].text;

  selObj.options[lineabove].text = selText;

  selObj.options[lineabove].value = selVal;

  selObj.options[thisline].value = upVal;

  selObj.options[thisline].text = upText;

  selObj.selectedIndex = lineabove;

} // end if

 

However, my if statements:

if (thisline > 3){

alert('Im sorry, you have reached the bottom')

}

 

Im trying to see if they are at the bottom, except i have hard coded it, and I do not want to do that. Is there an easier way to tell the user they are at the bottom of the table and can not move anymore?

[lemmin]

selObj.children.length should give you the number of items in the list and you can subtract one from it to get the last index.