javascript - Two if statements are always linked even if it's not true -

i have 2 separate if else statements. if think 1 true, other gets called , vice versa. here is

the first one

if (pension < 0 ) {     alert("pension value error. try again."); }  else if (pension > income) {     alert("rrsp contribution cannot exceed income."); } 

the second one

if (uniondues < 0 ) {     alert("union dues value error. try again."); }  else if (uniondues > (income - pension)) {     alert("union dues cannot exceed income less rrsp contribution"); } 

the if(pension > income) , if(uniondues > (income - pension)) call each other.

the variable income prompted before hand , checks after check if values valid.

if income 100, , pension 50 , uniondues 60, think should call second if else statement calls both.

if income 1, , pension 2, , uniondues 0, both alerts alerted well. know issue is?

edit: fix simple, parsefloat() , worked.

first off, should make sure 3 of values numbers, not strings because string comparisons not work numbers have different number of digits. want here actual number. if these come users typing data, have convert them numbers using parseint(nnn, 10).

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then, once numbers, logic has problems.

if pension greater income, both else if statements true.

the first else if obvious since it's direct else if (pension > income) , if pension positive, not match first if.

the second else if (uniondues > (income - pension)) match because income - pension negative means position value uniondues match condition.

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if want 1 alert ever triggered, can put 4 conditions same logic statement either using 1 if , 3 else if or other form of comparison ever selects 1 condition.

another possible solution accumulate error strings and, if error string non-empty @ end, show 1 alert error conditions in it.

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perhaps need show first error encoutered (if values true numbers):

if (pension < 0 ) {     alert("pension value error. try again."); } else if (pension > income) {     alert("rrsp contribution cannot exceed income."); } else if (uniondues < 0 ) {     alert("union dues value error. try again."); } else if (uniondues > (income - pension)) {     alert("union dues cannot exceed income less rrsp contribution"); }