A method of calculating the function and giving the corresponding curve picture (paste)

function <script language= "JavaScript" >
<!--Begin
var A, b, C;
function Xtop (form) {
Form.u.value = (Form.b.value *-1)/(Form.a.value * 2);
}
function Ytop (form) {
Form.u2.value =-1 * (Form.b.value * form.b.value)/(4 * form.a.value)-( -1 * form.c.value);
}
function Docoord (form) {
Form.co.value = Form.u.value + "," + form.u2.value;
}
function disc (form) {
Form.o.value = (Form.b.value * form.b.value)-(Form.a.value * form.c.value * 4);
}
function Zeroes1 (form) {
Form.n.value = ((Form.b.value *-1)-(MATH.SQRT (Form.o.value)))/(Form.a.value * 2);
}
function Zeroes2 (form) {
Form.n2.value = ((Form.b.value *-1)-( -1 * MATH.SQRT (Form.o.value)))/(Form.a.value * 2);
}
function move_in (IMG_NAME,IMG_SRC) {
DOCUMENT[IMG_NAME].SRC=IMG_SRC;
}
End-->
</script>
<form>
<table bgcolor= "#C0C0C0" cellspacing=2 cellpadding=2 border=3>
<tr>
<td>
<b>
<input name= "A" size= "3" >x²+
<input name= "B" size= "3" >x +
<input name= "C" size= "3" >
<br>
<input type= "button" value= "X-top" name= "X-top" onclick= "Xtop (this.form)" >
<input type= "button" value= "Y-top" name= "Y-top" onclick= "Ytop (this.form)" >
<input type= "button" value= "CRD" name= "CRD" onclick= "Docoord (this.form)" >
<input type= "button" value= "disc." Name= "D" onclick= "disc (This.form)" >
<br>
<input type= "button" value= "0-points" name= "zeroes" onclick= "zeroes1 (This.form); Zeroes2 (this.form)" >
<input type= "button" onclick= "Xtop (This.form); Ytop (This.form);d Ocoord (this.form);d ISC (this.form); Zeroes1 ( This.form) Zeroes2 (this.form) "value=" do all >
<input type= "button" name= "Pics" value= "show e.g." onclick= "if (form.a.value>0 && form.o.value>0) move _in (' P ', ' p2.gif '); if (form.a.value<0 && form.o.value>0) move_in (' P ', ' p3.gif '); if (form.a.value>0 && form.o.value==0) move_in (' P ', ' p4.gif '); if (form.a.value<0 && form.o.value==0) move_in (' P ', ' p5.gif '); if (form.a.value>0 && form.o.value<0) move_in (' P ', ' p6.gif '); if (form.a.value<0 && form.o.value<0) move_in (' P ', ' P7.gif ') "value=" show e.g. ">
<br>
<input type= "text" name= "U" size= "8" > X-top<br>
<input type= "text" Name= "U2" size= "8" > Y-top<br>
<input type= "Text" size= "8" name= "CO" onmouseover= "Form.rem.value=form.co.value" > Coord.<br>
<input type= "Text" size= "8" name= "O" > discriminant<br>
<input type= "Text" size= "8" name= "n" > Neg zero pt.<br>
<input type= "Text" size= "8" name= "N2" > Pos Zero pt.
<input type= "hidden" value= "" Name= "REM" ><br>
<input type= "reset" value= "reset" ><br>
</b>
</td>
<td></td >
</tr>
</table>
</form>