General :: Shell Script Is Showing Error After Whenever Checking A Special Variable

I have created a shell script to customise mv command, now i have achieved to accomplish all the functionality of mv by using alias. But i found difficulty in accomplish the funcionality with options [Like mv -i or mv -f etc.]. I thought about logic which check the first argument whether its starting with a minus [-] or not. if its starting with argument it will set a flag and execute accordingly. But whenever this condition is checked it shell script will throw error of destination operand missing. But the same will work with out option.

Note: I have used an minus[-] expression for decreasing a counter on the script above. The below mentioned is the portion of script. Sry for troubling Im not gud @scripting.

for i in $*
do
{
argument=`expr $argument - 1`
if [ $argument = 0 ];
then
exit
[Code]....