Interaction between dropdownlist (display and hide)

Copy codeThe Code is as follows:
<Script language = "javascript" type = "text/javascript">

Var Arrchange1 = new Array ();
Var Arrchange2 = new Array ();
Var Arrchange3 = new Array ();
Function hide (s_id, index)
{
Var xxx = document. getElementById (s_id );
Var oldOption = xxx. children (index );
Var oldStr = oldOption. innerText;
Var newOption = document. createElement ('<div' + oldOption. outerHTML. match (/(<\ w *) ([^>] *) (>)/) [2] + '> ');
NewOption. innerText = oldStr;
NewOption. swapNode (oldOption );
// Alert (xxx. innerHTML );
}

Function show (s_id, index)
{
Var xxx = document. getElementById (s_id );
Var oldOption = xxx. children (index );
If (oldOption. tagName = 'div ')
{
Var oldStr = oldOption. innerText;
Var newOption = document. createElement ('<option' + oldOption. outerHTML. match (/(<\ w *) ([^>] *) (>)/) [2] + '> ');
NewOption. innerText = oldStr;
NewOption. swapNode (oldOption );
}
// Alert (xxx. innerHTML );
}



Function onchange1 ()
{
Var s_index = document. getElementById ("Ddl_question1"). options [document. getElementById ("Ddl_question1"). selectedIndex]. value;
S_index = parseInt (s_index );
If (s_index = 0)
{
Show ('ddl _ question2 ', Arrchange1 [0]);
Show ('ddl _ question3', Arrchange1 [0]);
Arrchange1.pop ();
}
Else
{
Arrchange1.push (s_index );
If (Arrchange1.length> 0)
{
Show ('ddl _ question2 ', Arrchange1 [0]);
}
If (Arrchange1.length> 0)
{
Show ('ddl _ question3', Arrchange1 [0]);
}
Hide ('ddl _ question2 ', s_index );
Hide ('ddl _ question3 ', s_index );
}
}
Function onchange2 ()
{
Var s_index = document. getElementById ("Ddl_question2"). options [document. getElementById ("Ddl_question2"). selectedIndex]. value;
S_index = parseInt (s_index );
If (s_index = 0)
{
Show ('ddl _ question1 ', Arrchange1 [0]);
Show ('ddl _ question3', Arrchange3 [0]);
Arrchange2.pop ();
}
Else
{
Arrchange2.push (s_index );
If (Arrchange2.length> 0)
{
Show ('ddl _ question1 ', Arrchange2 [0]);
}
If (Arrchange2.length> 0)
{
Show ('ddl _ question3', Arrchange2 [0]);
}
Hide ('ddl _ question1 ', s_index );
Hide ('ddl _ question3 ', s_index );
}
}
Function onchange3 ()
{
Var s_index = document. getElementById ("Ddl_question3"). options [document. getElementById ("Ddl_question3"). selectedIndex]. value;
S_index = parseInt (s_index );
If (s_index = 0)
{
Show ('ddl _ question1 ', Arrchange3 [0]);
Show ('ddl _ question2 ', Arrchange3 [0]);
Arrchange3.pop ();
}
Else
{
Arrchange3.push (s_index );
If (Arrchange1.length> 0)
{
Show ('ddl _ question1 ', Arrchange3 [0]);
}
If (Arrchange2.length> 0)
{
Show ('ddl _ question2 ', Arrchange3 [0]);
}
Hide ('ddl _ question1 ', s_index );
Hide ('ddl _ question2 ', s_index );
}
}

Function a () {alert ("fuck ");}
</Script>

<Select name = "Ddl_question1" id = "Ddl_question1" onchange = "onchange1 ()">
<Option value = "0"> select Confidential Information </option>
<Option value = "1"> What is your mother's name? </Option>
<Option value = "2"> what is your father's name? </Option>
<Option value = "3"> what is the name of your spouse? </Option>
<Option value = "4"> where is your birthplace? </Option>
<Option value = "5"> what is the name of your high school class teacher? </Option>
<Option value = "6"> what is the name of your junior high school class teacher? </Option>
<Option value = "7"> what is the name of your primary school class teacher? </Option>
<Option value = "8"> What is your primary school name? </Option>
<Option value = "9"> what is your student ID (or employee ID? </Option>
<Option value = "10"> what is your father's birthday? </Option>
<Option value = "11"> What is your mother's birthday? </Option>
<Option value = "12"> what is your spouse's birthday? </Option>

</Select>
<Select name = "Ddl_question2" id = "Ddl_question2" onchange = "onchange2 ()">
<Option value = "0"> select Confidential Information </option>
<Option value = "1"> What is your mother's name? </Option>
<Option value = "2"> what is your father's name? </Option>
<Option value = "3"> what is the name of your spouse? </Option>
<Option value = "4"> where is your birthplace? </Option>
<Option value = "5"> what is the name of your high school class teacher? </Option>
<Option value = "6"> what is the name of your junior high school class teacher? </Option>
<Option value = "7"> what is the name of your primary school class teacher? </Option>
<Option value = "8"> What is your primary school name? </Option>
<Option value = "9"> what is your student ID (or employee ID? </Option>
<Option value = "10"> what is your father's birthday? </Option>
<Option value = "11"> What is your mother's birthday? </Option>
<Option value = "12"> what is your spouse's birthday? </Option>

</Select>
<Select name = "Ddl_question3" id = "Ddl_question3" onchange = "onchange3 ()">
<Option value = "0"> select Confidential Information </option>
<Option value = "1"> What is your mother's name? </Option>
<Option value = "2"> what is your father's name? </Option>
<Option value = "3"> what is the name of your spouse? </Option>
<Option value = "4"> where is your birthplace? </Option>
<Option value = "5"> what is the name of your high school class teacher? </Option>
<Option value = "6"> what is the name of your junior high school class teacher? </Option>
<Option value = "7"> what is the name of your primary school class teacher? </Option>
<Option value = "8"> What is your primary school name? </Option>
<Option value = "9"> what is your student ID (or employee ID? </Option>
<Option value = "10"> what is your father's birthday? </Option>
<Option value = "11"> What is your mother's birthday? </Option>
<Option value = "12"> what is your spouse's birthday? </Option>

</Select>