Would like to declare a variable Public/Global in an IF statement

Question

Is there way to declare a variable as Public in an IF statement. My goal is to declare the variable as global (since this variable is used somewhere in the code and should not get initialized when there is loop back to the top of the code, hence using IF statement to control the initialization) based on the IF condition and then use it elsewhere in the code.
I have it like this
if (!sei_second_jsp.equals("1"))
public int[] mecitem;
public String[] sei_mfg_prod_cat;
public String[] sei_part_number;
public String[] sei_descrip;
public String[] sei_price;
public int[] sei_onhand;
public int[] sei_demand;
mecitem = new int[20000];
sei_mfg_prod_cat = new String[20000];
sei_part_number = new String[20000];
sei_descrip = new String[20000];
sei_price = new String[20000];
sei_onhand = new int[20000];
sei_demand = new int[20000];
for (int i=0; i<=19999; i++)
mecitem[i] = 0;
sei_mfg_prod_cat[i] = " ";
sei_part_number[i] = " ";
sei_descrip[i] = " ";
sei_price[i] = " ";
sei_onhand[i] = 0;
sei_demand[i] = 0;
Your guess is right, I am using this code in JSP - since this is a Java related question, thought of posting it in JAVA forum.
When I use the above code, I get the following error
1809 }' expected. { 
1811 Statement expected. public int[] mecitem;
1827 Identifier expected. mecitem = new int[20000];
1827 Can't specify array dimension in a declaration. mecitem = new int[20000];
1827 Identifier expected. mecitem = new int[20000];
1837 Can't specify array dimension in a declaration. sei_onhand = new int[20000];
1837 Identifier expected. sei_onhand = new int[20000];
1839 Can't specify array dimension in a declaration. sei_demand = new int[20000];
1839 Identifier expected. sei_demand = new int[20000];
3117 Class or interface declaration expected. }

Answer 1

Please note the above code in the JSP is submitting to itself and I donot want it to get initialized if the IF statement is not successful..
thnks a lot for your time.. !!!