regrex required for fetching value in </span> : I need a regex for fetching the value in the </span> tag

<span class="booking-id-value">U166097</span
value required =U166097

can please someone suggest me. I have tried using 
<span class="booking-id-value">(.+?)  but it is not deriving the desired result it display on "U"

Please help me to get this desired value

Thanks