Caml Querry Example Using AND and IN Operator

var strQry="";

 strQry = '<Query><Where><And><And><Eq><FieldRef Name="ResourceName" /><Value Type="Text">' + resourceName + '</Value></Eq><And><Leq><FieldRef Name="EndDate" /><Value IncludeTimeValue="FALSE" Type="DateTime">' + lastdayval + '</Value></Leq><Geq><FieldRef Name="StartDate" /><Value IncludeTimeValue="FALSE" Type="DateTime">' + firstdayval + '</Value></Geq></And></And><In> <FieldRef Name="ProjectName" /><Values>'
    $.each(proNameArry, function (i, proName) {
        strQry += '<Value Type="text">' + proName + '</Value>'
    });
    strQry += '</Values></In></And></Where></Query>'


Sample CAML Querry Using AND and IN Operator:
<Query>
<Where>
<And>
<And>
<Eq><FieldRef Name="ResourceName" /><Value Type="Text">' + resourceName + '</Value></Eq>
<And>
<Leq><FieldRef Name="EndDate" /><Value IncludeTimeValue="FALSE" Type="DateTime">' + lastdayval + '</Value></Leq>
<Geq><FieldRef Name="StartDate" /><Value IncludeTimeValue="FALSE" Type="DateTime">' + firstdayval + '</Value></Geq>
</And>
</And>
<In> <FieldRef Name="ProjectName" /><Values><Value Type="text">Test12324</Value></Values></In>
</And>
</Where>

</Query>