slider is not showing

slider is not showing

Hi I am new to using jquery plugins...i am using a slider but its not showing. can any one help me at the earliest plz...
 
My code is as below:

<

 html xmlns ="http://www.w3.org/1999/xhtml" >

<

 head runat ="server">

< title > Untitled Page </ title >

< link type ="text/css" href ="css/themename/jquery-ui-1.8.6.custom.css" rel ="Stylesheet" />

< script type ="text/javascript" src ="js/jquery-1.4.2.min.js"></ script >

< script type ="text/javascript" src ="js/jquery-ui-1.8.6.custom.min.js"></ script >

< script >

$(

 function () {

$(

"#slider" ).slider({

value:300,

min: 0,

max: 500,

step: 50,

slide:

function ( event , ui ) {

$(

"#amount" ).val( "$" + ui.value );

}

});

$(

"#amount" ).val( "$" + $( "#slider" ).slider( "value" ) );

});

$(

 '#slider' ).slider({

orientation:

'vertical'

});

 </ script >

</

 head >

<

 body >

< form id ="form1" runat ="server">

< div id ="slider" visible ="true"></ div >

</ form >

</

 body >

</
html >
 
 
Thanks,
Swathi