Solaris下shell的if语句问题

在Solaris创建目录的shell脚本：
#!/bin/sh
#ifmkdir
#parameter is passed as $1 but reassigned to DIRECTORY
DIRECTORY=$1
#is the string empty??
if [ "$DIRECTORY" = "" ]
then
echo "Usage: `basename $0` directory to create" >&2
exit 1
fi

if[ ! -d $DIRECTORY ]
then
echo "The directory does't exist" #14行
echo -n "Create it now? [y..n] :"
read ANS
if [ "$ANS" = "y" || "$ANS" = "Y" ]
then
echo "creating now"
#create directory and send all output to /dev/null
mkdir $DIRECTORY >/dev/null 2>&1
if [ $? != 0 ]
then
echo "Errors creating the directory $DIRECTORY" >&2
exit 1
fi
fi
fi

执行该脚本：./ifmkdir.sh kkk
报错如下：
./ifmkdir.sh: if[: 没找到
./ifmkdir.sh: 语法错误在14行：`then' 非期望的

请各位大侠帮帮忙，我刚学习shell，希望大家帮忙指点一下，谢谢！！！