clientid coming incorrect

[Vikram]

is someone has faced this kind of problem...
I am using clientid porperty of server control in this manner in a
javascript
alert('<%=txt.clientid%>')

now first time it give some spaces in the clientid , but when i use this
second time in same code below, it give correct clientid value. Like if i
give this , it will work alright

//alert('<%=txt.clientid%>')
alert('<%=txt.clientid%>')

any idea why is it hapenig

I am using this contol in ascx file, which is being loaded by microsoft
multipage control into a aspx file