<html>
<body>
<FORM name="isc">
<table border="0" cellspacing="0" cellpadding="0">
<tr align="center">
<td nowrap height="11">
<select name="example" size="1" onChange="redirect(this.options.selectedIndex)">
<option selected>Elige una marca</option>
<option>Audi</option>
<option>BMW</option>
</select>
<select name="stage2" size="1" onChange="redirect1(this.options.selectedIndex)">
<option value=" " selected>Elige un modelo</option>
</select>
<select name="stage3" size="1" onChange="redirect2(this.options.selectedIndex)">
<option value=" " selected>Elige un coche</option>
</select>
<script>
var groups=document.isc.example.options.length
var group=new Array(groups)
for (i=0; i<groups; i++)
group[i]=new Array()
group[0][0]=new Option("Elige un modelo"," ");
group[1][0]=new Option("Elige un modelo"," ");
group[1][1]=new Option("A2"," ");
group[1][2]=new Option("A3","47");
group[1][3]=new Option("A4","46");
group[1][4]=new Option("A6","45");
group[1][5]=new Option("A8","44");
group[1][6]=new Option("TT","43");
group[1][7]=new Option("S4","42");
group[1][8]=new Option("S6","41");
group[1][9]=new Option("RS6","40");
group[1][10]=new Option("Cabrio","39");
group[1][11]=new Option("Allroad quattro","38");
group[2][0]=new Option("Elige un modelo"," ");
group[2][1]=new Option("Serie 1"," ");
group[2][2]=new Option("Serie 3","115");
group[2][3]=new Option("Serie 5","116");
group[2][4]=new Option("Serie 6","117");
group[2][5]=new Option("Serie 7","118");
group[2][6]=new Option("X3","119");
group[2][7]=new Option("X5","120");
group[2][8]=new Option("Z4","121");
var temp=document.isc.stage2
function redirect(x){
for (m=temp.options.length-1;m>0;m--)
temp.options[m]=null
for (i=0;i<group[x].length;i++){
temp.options[i]=new Option(group[x][i].text,group[x][i].value)
}
temp.options[0].selected=true
redirect1(0)
}
var secondGroups=document.isc.stage2.options.length
var secondGroup=new Array(groups)
for (i=0; i<groups; i++) {
secondGroup[i]=new Array(group[i].length)
for (j=0; j<group[i].length; j++){
secondGroup[i][j]=new Array()
}
}
secondGroup[0][0][0]=new Option("Elige un coche"," ");
secondGroup[1][0][0]=new Option("Elige un coche"," ");
secondGroup[1][1][0]=new Option("Elige un coche"," ");
secondGroup[1][1][1]=new Option("Audi 1.2 TDI","");
secondGroup[1][1][2]=new Option("Audi 1.4","");
secondGroup[1][1][3]=new Option("Audi 1.4 TDI 75 CV","");
secondGroup[1][1][4]=new Option("Audi 1.6 FSI","");
secondGroup[1][1][5]=new Option("Audi 1.4 TDI 90 CV","");
secondGroup[1][1][6]=new Option("Audi 1.4 colour storm","");
secondGroup[1][1][7]=new Option("Audi 1.4 TDI 75 CV colour storm","");
secondGroup[1][1][8]=new Option("Audi 1.6 FSI colour storm","");
secondGroup[1][1][9]=new Option("Audi 1.4 TDI 90 CV colour storm","");
secondGroup[1][2][0]=new Option("Elige un coche"," ");
secondGroup[1][2][1]=new Option("A3 1.6 Attraction","");
secondGroup[1][2][2]=new Option("A3 1.6 Ambition","");
secondGroup[1][2][3]=new Option("A3 1.6 Ambiente","");
secondGroup[1][3][0]=new Option("Elige un coche"," ");
secondGroup[1][3][1]=new Option("A4","");
secondGroup[1][3][2]=new Option("A4","");
secondGroup[2][0][0]=new Option("Elige un coche"," ");
secondGroup[2][1][0]=new Option("Elige un coche"," ");
secondGroup[2][1][1]=new Option("Serie 1","");
secondGroup[2][1][2]=new Option("Serie 1","");
secondGroup[2][1][3]=new Option("Serie 1","");
secondGroup[2][2][0]=new Option("Elige un coche"," ");
secondGroup[2][2][1]=new Option("Serie 3","");
secondGroup[2][2][2]=new Option("Serie 3","");
var temp1=document.isc.stage3
function redirect1(y){
for (m=temp1.options.length-1;m>0;m--)
temp1.options[m]=null
for (i=0;i<secondGroup[document.isc.example.options.selectedIndex][y].length;i++){
temp1.options[i]=new Option(secondGroup[document.isc.example.options.selectedIndex][y][i].text,secondGroup[document.isc.example.options.selectedIndex][y][i].value)
}
temp1.options[0].selected=true
}
/*function redirect2(z){
window.location=temp1[z].value
}*/
</script>
</td>
</tr>
</table><br>
<input type=submit value="Adelante">
</FORM>
</body>
</html>
El triple combo está resuelto, porque ya solo quedaría cambiar los valores de cada combo. Pero aún tengo una pequeña duda, porque necesito crear una función que controle lo siguiente:
Si el valor del primer combo y del segundo es el inicial (en mi caso, "Elegir una marca" y "Elegir un modelo"), cuando le doy al botón salta un alert que diga que hace falta seleccionar una marca y un modelo para continuar. Si no, hace lo que tenga que hacer. ¿Cómo puedo conseguir eso? Muchas gracias
