请教：脚本有什么语法错误

lalala

#!/bin/sh
wait=10
echo " please waiting "+ $wait+" seconds for jboss startup..."
sh /usr/local/jboss-3.0.8_tomcat-4.1.24/bin/run.sh>;/tmp/jboss.up1&
sleep $wait
running='cat /tmp/jboss.up1|grep MircoKernel'
if [ "x"="x$running" ]
then
exit 1
else
rm -f /tmp/jboss.up1
fi

result is:

+ seconds for jboss startup...
: command not found
'leep: invalid time interval `10
请尝试执行‘sleep --help’来获取更多信息。
restore: line 13: syntax error: unexpected end of file

bjgirl

running='cat /tmp/jboss.up1|grep MircoKernel'  #将一个命令的输出给一个变量要用反引号
if [ "x"="x$running" ] #[]中各项要有空格

lalala

请问“反引号”是什么？