How to look certain values from javascript table

[CaesarTapsa]

I'm sorry I don't know how to put my code in PHP block.

</br>
<PHP>
//Here I have part of my javascript table
pisteet[6][0] = prompt("Tunnistenumero:", "3")
pisteet[6][1] = prompt("Tunnistenimi:", "1")
pisteet[6][2] = Number(prompt("X-koordinaatti:", 4572))
pisteet[6][3] = Number(prompt("Y-koordinaatti:", 1654))
pisteet[7][0] = prompt("Tunnistenumero:", "15")
pisteet[7][1] = prompt("Tunnistenimi:", "1")
pisteet[7][2] = Number(prompt("X-koordinaatti:", 8442))
pisteet[7][3] = Number(prompt("Y-koordinaatti:", 5624))
pisteet[8][0] = prompt("Tunnistenumero:", "21")
pisteet[8][1] = prompt("Tunnistenimi:", "1")
pisteet[8][2] = Number(prompt("X-koordinaatti:", 3214))
pisteet[8][3] = Number(prompt("Y-koordinaatti:", 9846))

//My purpose is to search two prompted points from the table above.
var p1 = prompt("Piste 1 suuntakulman ja matkan laskemista varten:", 3)
var p2 = prompt("Piste 2 suuntakulman ja matkan laskemista varten:", 21)
//No, those numbers aren't really numbers so I am not looking for numbers in the table.

//Following do-while searches doesn't work because they look numbers?
i=1
do
{
i++;
if(i == 100) break;
}
while(pisteet[i][0] = p1)

j=1
do
{
j++;
if(j == 100) break;
}
while(pisteet[j][0] = p2)
//So I want to input any two point number (Tunnistenumero) in promt p1 and p2 and calculate difference in Y-coordinates.

var etaisyys = ((pisteet[j][3]-pisteet[i][3]))
document.write("<p>joo ",etaisyys," ",pisteet[i][3]);
//pisteet[i][3] should write 1654
</PHP>
</br>

It might help you if I would upload the whole javascript, but as you requested, I didn't.

So, basically I have a table of points with coordinates and I want to calculate difference in Y-coordinates between any of them.
I want to search points by their name (point numbers/tunnistenumero).

I'll try to make it more clearer:

Question: pisteet[?][0] = "3"
Answer should be: pisteet[6][0] = "3"

With above question how I can get above answer in javascript?
The rest I can do by myself.

Did you get what I want to do with javascript? (Because I doubt that you got it, but I did my best at pointing out the question so if nobody understands what I try to do, then never mind.)

[Kor]

quite muddy your code. At a first glance, I can note that document.write() is not a dynamic method.

On the other hand, a conditional while loop must have a Boolean as condition. A simple assignment like

while(pisteet[j][0] = p2)

will not return a Boolean unless the second term is undefined/false/null (which is not your case). I guess you need a comparison operator:

while(pisteet[j][0] == p2)

But, as this possibility is unique, I don't sense whay you have not used a sinple if(){} statement. Or a switch/case one. Or probably you want to loop the array till both terms are the same. In this case, probably you need:

while(pisteet[j][0] != p2)

As I said, I don't understand very well your aim... Nor your syntax.

[CaesarTapsa]

How can I use simple if(){} statement? (Can not be googled.)
is it something like:

pisteet[8][0] = prompt("Tunnistenumero:", "21")

var p2 = prompt("Piste 2 suuntakulman ja matkan laskemista varten:", 21)

if(pisteet[j][0] == p2){j=8}

var etaisyys = ((pisteet[j][3]-pisteet[i][3]))
document.write(etaisyys) 

(And it may not be unique, but that can be forgotten.)

[Kor]

How can I use simple if(){} statement? (Can not be googled.)
is it something like:

pisteet[8][0] = prompt("Tunnistenumero:", "21")

var p2 = prompt("Piste 2 suuntakulman ja matkan laskemista varten:", 21)

if(pisteet[j][0] == p2){j=8}

var etaisyys = ((pisteet[j][3]-pisteet[i][3]))
document.write(etaisyys) 

(And it may not be unique, but that can be forgotten.)

OK. You have just used a "simple if(){} statement". So? Which is the problem?

[CaesarTapsa]

I changed my code a lot and here is some parts of it:

<FORM NAME = lom0>
<table width="800"><tr>
<td>ID: 6</td>
<td>Piste: <INPUT TYPE=Text NAME=syo60 SIZE=4 value="6"></td>
<td>Kuvaus: <INPUT TYPE=Text NAME=syo61 SIZE=12 value="Tasokiintopiste"></td>
<td>X: <INPUT TYPE=Text NAME=syo62 SIZE=10 value="4572.000"></td>
<td>Y: <INPUT TYPE=Text NAME=syo63 SIZE=10 value="1654.000"></td>
<td>Z: <INPUT TYPE=Text NAME=syo64 SIZE=7 value="0.000"></td></tr><tr>
<td>ID: 7</td>
<td>Piste: <INPUT TYPE=Text NAME=syo70 SIZE=4 value="7"></td>
<td>Kuvaus: <INPUT TYPE=Text NAME=syo71 SIZE=12 value="Tasokiintopiste"></td>
<td>X: <INPUT TYPE=Text NAME=syo72 SIZE=10 value="8442.000"></td>
<td>Y: <INPUT TYPE=Text NAME=syo73 SIZE=10 value="5624.000"></td>
<td>Z: <INPUT TYPE=Text NAME=syo74 SIZE=7 value="0.000"></td></tr><tr>
<td>ID: 8</td>
<td>Piste: <INPUT TYPE=Text NAME=syo80 SIZE=4 value="8"></td>
<td>Kuvaus: <INPUT TYPE=Text NAME=syo81 SIZE=12 value="Tasokiintopiste"></td>
<td>X: <INPUT TYPE=Text NAME=syo82 SIZE=10 value="3214.000"></td>
<td>Y: <INPUT TYPE=Text NAME=syo83 SIZE=10 value="9846.000"></td>
<td>Z: <INPUT TYPE=Text NAME=syo84 SIZE=7 value="0.000"></td></tr><tr>
</table><hr>
</FORM> 

<script type="text/javascript">
var pisteet = new Array(11)
pisteet[0] = new Array(4)
pisteet[1] = new Array(4)
pisteet[2] = new Array(4)
pisteet[3] = new Array(4)
pisteet[4] = new Array(4)
pisteet[5] = new Array(4)
pisteet[6] = new Array(4)
pisteet[7] = new Array(4)
pisteet[8] = new Array(4)
pisteet[9] = new Array(4)
pisteet[10] = new Array(4)

function otapis() {

pisteet[6][0] = document.lom0.syo60.value
pisteet[6][1] = document.lom0.syo61.value
pisteet[6][2] = document.lom0.syo62.value
pisteet[6][3] = document.lom0.syo63.value
pisteet[7][0] = document.lom0.syo70.value
pisteet[7][1] = document.lom0.syo71.value
pisteet[7][2] = document.lom0.syo72.value
pisteet[7][3] = document.lom0.syo73.value
pisteet[8][0] = document.lom0.syo80.value
pisteet[8][1] = document.lom0.syo81.value
pisteet[8][2] = document.lom0.syo82.value
pisteet[8][3] = document.lom0.syo83.value

}

function matka() {
p1 = document.lom1.piste1.value
p2 = document.lom1.piste2.value
if(pisteet[i][0] != p1)
if(pisteet[j][0] != p2)
A = (pisteet[j][3] - pisteet[i][3])
B = (pisteet[j][2] - pisteet[i][2])
C = Math.sqrt(A*A+B*B)
document.lom1.eta.value = C
}
</script> 

<FORM NAME = lom1>
Pisteen 1 ID: <INPUT TYPE = Text NAME = piste1 SIZE = 5 value ="6">
&nbsp;&nbsp;&nbsp;Pisteen 2 ID: <INPUT TYPE = Text NAME = piste2 SIZE = 5 value ="8">
<P>
Matka 1&#8594;2: <INPUT TYPE="Text" NAME="eta" SIZE=5 value="">
<P>
<Input Type="Button" NAME="b1" VALUE="Laske suunta ja matka" onClick="otapis();matka()">
</FORM><hr> 

Nothing comes into answer form box.

I got this working by referring to "ID:" from the table instead of referring to "Piste:"

But because "ID:" and "Piste:" can be different, I'd like to search exact cell row which has its [n][0] value same as what user will type into form box "piste1" (or "piste2"). if(pisteet[i][0] != p1) seems unable to do it.

[Kor]

if(pisteet[i][0] != p1)
if(pisteet[j][0] != p2)

Where are those variable defined? Do you intend to perform a loop?:
http://www.w3schools.com/JS/js_loop_for.asp